REF: BBONE_SRM BeagleBone System Reference Manual RevA5.0.1 BeagleBone Rev A5 System Reference Manual Revision 0.1 February 2, 2012 Send all comments and errors to the author: Gerald Coley gerald@beagleboard.org Page 1 of 83 REF: BBONE_SRM BeagleBone System Reference Manual RevA5.0.1 NOTE: This equipment has been tested and found to comply with the limits for a Class B digital device, pursuant to Part 15 of the FCC Rules. These limits are designed to provide reasonable protection against harmful interference when the equipment is operated in a commercial environment. This equipment generates, uses, and can radiate radio frequency energy and, if not installed and used in accordance with the instruction manual, may cause harmful interference to radio communications. Operation of this equipment in a residential area is likely to cause harmful interference in which case the user will be required to correct the interference at their own expense. All accessories used with this board must meet FCC certification to maintain compliance of this equipment. NOTE:. If this equipment does cause harmful interference to radio or television reception, which can be determined by turning the equipment off and on, the user is encouraged to try to correct the interference by one or more of the following measures: —Reorient or relocate the receiving antenna. —Increase the separation between the equipment and receiver. —Connect the equipment into an outlet on a circuit different from that to which the receiver is connected. —Consult the dealer or an experienced radio/TV technician for help. Changes or modifications not expressly approved by this manual for compliance could void the user’s authority to operate the equipment. THIS DOCUMENT This work is licensed under the Creative Commons Attribution-Share Alike 3.0 Unported License. To view a copy of this license, visit http://creativecommons.org/licenses/bysa/3.0/ or send a letter to Creative Commons, 171 Second Street, Suite 300, San Francisco, California, 94105, USA. All derivative works are to be attributed to Gerald Coley of BeagleBoard.org. For more information, see http://creativecommons.org/license/resultsone?license_code=by-sa For any questions, concerns, or issues submit them to gerald@BeagleBoard.org Page 2 of 83 REF: BBONE_SRM BeagleBone System Reference Manual RevA5.0.1 BEAGLEBONE DESIGN These design materials referred to in this document are *NOT SUPPORTED* and DO NOT constitute a reference design. Only “community” support is allowed via resources at BeagleBoard.org/discuss. THERE IS NO WARRANTY FOR THE DESIGN MATERIALS, TO THE EXTENT PERMITTED BY APPLICABLE LAW. EXCEPT WHEN OTHERWISE STATED IN WRITING THE COPYRIGHT HOLDERS AND/OR OTHER PARTIES PROVIDE THE DESIGN MATERIALS “AS IS” WITHOUT WARRANTY OF ANY KIND, EITHER EXPRESSED OR IMPLIED, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. THE ENTIRE RISK AS TO THE QUALITY AND PERFORMANCE OF THE DESIGN MATERIALS IS WITH YOU. SHOULD THE DESIGN MATERIALS PROVE DEFECTIVE, YOU ASSUME THE COST OF ALL NECESSARY SERVICING, REPAIR OR CORRECTION. We mean it; these design materials may be totally unsuitable for any purposes. Page 3 of 83 REF: BBONE_SRM BeagleBone System Reference Manual RevA5.0.1 BeagleBoard.org provides the enclosed product(s) under the following conditions: This evaluation board/kit is intended for use for ENGINEERING DEVELOPMENT, DEMONSTRATION, OR EVALUATION PURPOSES ONLY and is not considered by BeagleBoard.org to be a finished end-product fit for general consumer use. Persons handling the product(s) must have electronics training and observe good engineering practice standards. As such, the goods being provided are not intended to be complete in terms of required design-, marketing-, and/or manufacturing-related protective considerations, including product safety and environmental measures typically found in end products that incorporate such semiconductor components or circuit boards. This evaluation board/kit does not fall within the scope of the European Union directives regarding electromagnetic compatibility, restricted substances (RoHS), recycling (WEEE), FCC, CE or UL, and therefore may not meet the technical requirements of these directives or other related directives. Should this evaluation board/kit not meet the specifications indicated in the User’s Guide, the board/kit may be returned within 30 days from the date of delivery for a full refund to the distributor form which you purchased the board. THE FOREGOING WARRANTY IS THE EXCLUSIVE WARRANTY MADE BY SELLER TO BUYER AND IS IN LIEU OF ALL OTHER WARRANTIES, EXPRESSED, IMPLIED, OR STATUTORY, INCLUDING ANY WARRANTY OF MERCHANTABILITY OR FITNESS FOR ANY PARTICULAR PURPOSE. The user assumes all responsibility and liability for proper and safe handling of the goods. Further, the user indemnifies BeagleBoard.org from all claims arising from the handling or use of the goods. Due to the open construction of the product, it is the user’s responsibility to take any and all appropriate precautions with regard to electrostatic discharge. EXCEPT TO THE EXTENT OF THE INDEMNITY SET FORTH ABOVE, NEITHER PARTY SHALL BE LIABLE TO THE OTHER FOR ANY INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES. BeagleBoard.org currently deals with a variety of customers for products, and therefore our arrangement with the user is not exclusive. BeagleBoard.org assumes no liability for applications assistance, customer product design, software performance, or infringement of patents or services described herein. Please read the System Reference Manual and, specifically, the Warnings and Restrictions notice in the User’s Guide prior to handling the product. This notice contains important safety information about temperatures and voltages. For additional information on BeagleBoard.org environmental and/or safety programs, please visit BeagleBoard.org. No license is granted under any patent right or other intellectual property right of BeagleBoard.org covering or relating to any machine, process, or combination in which such BeagleBoard.org products or services might be or are used. Mailing Address: BeagleBoard.org 1380 Presidential Dr. #100 Richardson, TX 75081 U.S.A. Page 4 of 83 REF: BBONE_SRM BeagleBone System Reference Manual RevA5.0.1 WARRANTY: The BeagleBoard is warranted against defects in materials and workmanship for a period of 90 days from purchase. This warranty does not cover any problems occurring as a result of improper use, modifications, exposure to water, excessive voltages, abuse, or accidents. All boards will be returned via standard mail if an issue is found. If no issue is found or express return is needed, the customer will pay all shipping costs. Before returning the board, please visit BeagleBoard.org/support Please refer to section 9 of this document for the board checkout procedures. To return a defective board, please request an RMA at http://beagleboard.org/support/rma Please DO NOT return the board without approval from the RMA team first. Page 5 of 83 REF: BBONE_SRM BeagleBone System Reference Manual RevA5.0.1 Table of Contents FIGURES ....................................................................................................................................................... 8 TABLES ......................................................................................................................................................... 9 1.0 INTRODUCTION ............................................................................................................................. 11 2.0 CHANGE HISTORY ........................................................................................................................ 11 2.1 CHANGE HISTORY ........................................................................................................................... 11 2.2 REV A4 VS. A5 ................................................................................................................................ 12 2.2.1 PCB Changes ........................................................................................................................ 12 2.2.2 Design Changes..................................................................................................................... 12 2.2.3 Production Changes .............................................................................................................. 12 2.3 REV A3 VS. A4 ................................................................................................................................ 13 2.3.1 PCB Changes ........................................................................................................................ 13 2.3.2 Design Changes..................................................................................................................... 13 3.0 BEAGLEBONE OVERVIEW .......................................................................................................... 14 3.1 3.2 3.3 4.0 BEAGLEBONE FEATURES AND SPECIFICATION ................................................................. 15 4.1 4.2 5.0 BEAGLEBONE EXPANSION ............................................................................................................... 14 BEAGLEBONE DESIGN MATERIAL ................................................................................................... 14 IN THE BOX ..................................................................................................................................... 14 BOARD COMPONENT LOCATIONS .................................................................................................... 16 BOARD CONNECTOR AND INDICATOR LOCATIONS .......................................................................... 18 BEAGLEBONE DESIGN SPECIFICATION................................................................................. 20 5.1 PROCESSOR...................................................................................................................................... 20 5.2 MEMORY ......................................................................................................................................... 20 5.3 POWER MANAGEMENT .................................................................................................................... 20 5.4 PC USB INTERFACE ........................................................................................................................ 20 5.4.1 Serial Debug Port.................................................................................................................. 21 5.4.2 JTAG Port ............................................................................................................................. 21 5.4.3 USB0 Port ............................................................................................................................. 21 5.5 MICROSD CONNECTOR ................................................................................................................... 21 5.6 USB1 PORT ..................................................................................................................................... 21 5.7 USB CLIENT PORT........................................................................................................................... 21 5.8 POWER SOURCES ............................................................................................................................. 22 5.9 RESET BUTTON ................................................................................................................................ 22 5.10 INDICATORS ................................................................................................................................ 22 5.11 CTI JTAG HEADER .................................................................................................................... 22 6.0 EXPANSION INTERFACE ............................................................................................................. 23 6.1 MAIN BOARD EXPANSION HEADER ................................................................................................. 23 6.2 CAPE EXPANSION BOARDS .............................................................................................................. 23 6.3 EXPOSED FUNCTIONS ...................................................................................................................... 24 6.3.1 LCD ....................................................................................................................................... 24 6.3.2 GPMC.................................................................................................................................... 24 6.3.3 MMC1.................................................................................................................................... 24 6.3.4 SPI ......................................................................................................................................... 24 6.3.5 I2C ......................................................................................................................................... 25 6.3.6 Serial Ports ............................................................................................................................ 25 6.3.7 A/D Converters ...................................................................................................................... 25 6.3.8 GPIO ..................................................................................................................................... 25 6.3.9 CAN Bus ................................................................................................................................ 25 Page 6 of 83 REF: BBONE_SRM 6.3.10 6.3.11 7.0 BeagleBone System Reference Manual RevA5.0.1 TIMERS ............................................................................................................................ 25 PWM ................................................................................................................................. 26 DETAILED BOARD DESIGN ......................................................................................................... 27 7.1 SYSTEM BLOCK DIAGRAM ............................................................................................................... 27 7.2 PROCESSOR...................................................................................................................................... 27 7.2.1 Processor Block Diagram ..................................................................................................... 28 7.3 SYSTEM POWER ............................................................................................................................... 29 7.3.1 TPS65217B PMIC ................................................................................................................. 29 7.3.2 5V DC Power Input ............................................................................................................... 32 7.3.3 USB Power ............................................................................................................................ 32 7.3.1 Power Source Selection ......................................................................................................... 33 7.3.2 Power Consumption .............................................................................................................. 33 7.3.3 Power Sequencing ................................................................................................................. 34 7.3.4 TPS65217B Power Up........................................................................................................... 34 7.3.5 Voltage Rails ......................................................................................................................... 35 7.3.6 Power Indicator LED ............................................................................................................ 36 7.3.7 Expansion 3.3V LDO ............................................................................................................. 37 7.4 CURRENT MEASUREMENT ............................................................................................................... 37 7.4.1 SYS_5V Connection ............................................................................................................... 37 7.4.2 SYS_VOLT Connection.......................................................................................................... 38 7.4.3 MUX_OUT Connection ......................................................................................................... 38 7.4.4 Current Calculation .............................................................................................................. 38 7.5 TWO PORT USB HUB...................................................................................................................... 38 7.5.1 Processor USB Port .............................................................................................................. 39 7.5.2 HUB Power ........................................................................................................................... 39 7.5.3 Crystal and Reset................................................................................................................... 39 7.5.4 FT2232H Serial Adapter ....................................................................................................... 40 7.5.5 Processor USB Port .............................................................................................................. 40 7.6 FT2232H USB TO SERIAL ADAPTER ............................................................................................... 41 7.6.1 EEPROM ............................................................................................................................... 41 7.6.2 JTAG...................................................................................................................................... 42 7.6.3 Serial Port ............................................................................................................................. 42 7.7 256MB DDR2 MEMORY ................................................................................................................. 42 7.7.1 DDR 2 Design ....................................................................................................................... 43 7.7.2 DDR VTP Termination Resistor ............................................................................................ 44 7.7.3 User LEDs ............................................................................................................................. 44 7.8 10/100 ETHERNET............................................................................................................................ 45 7.8.1 Ethernet PHY Design ............................................................................................................ 45 7.8.2 Processor Signal Description ................................................................................................ 46 7.8.3 Clocking Mode ...................................................................................................................... 47 7.8.4 PHY Mode ............................................................................................................................. 47 7.8.5 MDIO Interface ..................................................................................................................... 48 7.8.6 PHY Reset .............................................................................................................................. 49 7.8.7 Status LEDs ........................................................................................................................... 49 7.8.8 Power .................................................................................................................................... 49 7.9 USB HOST ....................................................................................................................................... 49 7.9.1 USB Host design .................................................................................................................... 49 7.10 SD CONNECTOR .......................................................................................................................... 50 7.11 EEPROM ................................................................................................................................... 51 7.12 ADC INTERFACE......................................................................................................................... 52 7.12.1 ADC Inputs ....................................................................................................................... 53 7.12.2 VDD_ADC Interface......................................................................................................... 53 7.13 EXPANSION HEADERS ................................................................................................................. 54 7.13.1 Expansion Header P8 ....................................................................................................... 54 Page 7 of 83 REF: BBONE_SRM 7.13.2 7.13.3 7.13.4 7.13.5 7.13.6 8.0 BeagleBone System Reference Manual RevA5.0.1 P8 Signal Pin Mux Options ............................................................................................. 55 Expansion Header P9 ....................................................................................................... 59 PMIC Expansion Header.................................................................................................. 64 Backlight Interface ........................................................................................................... 64 Battery Interface ............................................................................................................... 65 CAPE BOARD SUPPORT ............................................................................................................... 66 8.1 EEPROM ........................................................................................................................................ 66 8.1.1 EEPROM Address ................................................................................................................. 67 8.1.2 I2C Bus .................................................................................................................................. 67 8.1.3 EEPROM Data Format ......................................................................................................... 68 8.1.4 Pin Usage .............................................................................................................................. 69 8.1.5 EEPROM Write Protect ........................................................................................................ 71 8.2 EXPANSION CONNECTORS ............................................................................................................... 72 8.2.1 Non-Stacking Headers-Single Cape ..................................................................................... 72 8.2.2 Battery Connector- Single ..................................................................................................... 73 8.2.3 Main Expansion Headers-Stacking ....................................................................................... 74 8.2.4 Battery Connector Stacking ................................................................................................... 75 8.2.5 Stacked Capes w/Signal Stealing........................................................................................... 75 8.3 SIGNAL USAGE ................................................................................................................................ 76 8.4 CAPE POWER ................................................................................................................................... 76 8.4.1 Main Board Power ................................................................................................................ 76 8.4.2 Expansion Board External Power ......................................................................................... 77 8.4.3 Mechanical ............................................................................................................................ 77 8.4.4 Standard Cape Size ............................................................................................................... 77 8.4.5 Extended Cape Size ............................................................................................................... 78 9.0 BOARD SETUP ................................................................................................................................. 79 9.1 CREATING A SD CARD .................................................................................................................... 79 9.2 USB POWERED SETUP ..................................................................................................................... 79 9.3 DC POWERED SETUP ....................................................................................................................... 79 9.4 ADVANCED TEST ............................................................................................................................. 80 9.4.1 Equipment Needed ................................................................................................................. 81 9.4.2 Procedure .............................................................................................................................. 81 9.4.3 Debugging ............................................................................................................................. 81 10.0 BEAGLEBONE MECHANICAL SPECIFICATION ............................................................... 82 11.0 DESIGN INFORMATION........................................................................................................... 83 Figures Figure 1. Figure 2. Figure 3. Figure 4. Figure 5. Figure 6. Figure 7. Figure 8. Figure 9. Figure 10. Top Side Components ................................................................................... 16 Bottom Side Components ............................................................................. 17 Board Connector and Indicators ................................................................... 18 Main Board Expansion Connector ................................................................ 23 System Block Diagram ................................................................................. 27 Processor Block Diagram ............................................................................. 28 Power Subsection Block Diagram ................................................................ 29 TPS65217B Block Diagram ......................................................................... 31 5V DC Power Input ...................................................................................... 32 USB Power Input ...................................................................................... 33 Page 8 of 83 REF: BBONE_SRM Figure 11. Figure 12. Figure 13. Figure 14. Figure 15. Figure 16. Figure 17. Figure 18. Figure 19. Figure 20. Figure 21. Figure 22. Figure 23. Figure 24. Figure 25. Figure 26. Figure 27. Figure 28. Figure 29. Figure 30. Figure 31. Figure 32. Figure 33. Figure 34. Figure 35. Figure 36. Figure 37. Figure 38. BeagleBone System Reference Manual RevA5.0.1 Power Sequencing..................................................................................... 34 RTC_PORZ Control ................................................................................. 35 Expansion 3.3V Regulator ........................................................................ 37 Current Measurement................................................................................ 38 USB HUB Design ..................................................................................... 39 FT2232H Design ....................................................................................... 41 DDR Device Block Diagram .................................................................... 43 DDR Design .............................................................................................. 43 User LEDS ................................................................................................ 44 10/100 Ethernet PHY Design.................................................................... 46 10/100 Ethernet PHY Default Settings ..................................................... 48 USB Host Design ...................................................................................... 50 SD Connector Design ............................................................................... 51 EEPROM Design ...................................................................................... 52 PMIC Expansion Header .......................................................................... 64 Backlight Circuitry.................................................................................... 64 Battery Circuitry ....................................................................................... 65 Expansion Board EEPROM ...................................................................... 66 Single Expansion Connector ..................................................................... 72 Single Cape Expansion Connector............................................................ 73 Battery/Backlight Expansion Connector................................................... 73 Expansion Connector ................................................................................ 74 Stacked Cape Expansion Connector ......................................................... 74 Stacked Battery Expansion Connector...................................................... 75 Stacked w/Signal Stealing Expansion Connector ..................................... 76 Cape Board Dimensions .......................................................................... 78 Board Top Profile ..................................................................................... 82 Board Bottom Profile ................................................................................ 82 Tables Table 1. Table 2. Table 3. Table 4. Table 5. Table 6. Table 7. Table 8. Table 9. Table 10. Table 11. Table 12. Table 13. Table 14. Table 15. Change History ............................................................................................. 11 BeagleBone Features .................................................................................... 15 BeagleBone Power Consumption(mA@5V) ................................................ 33 DDR Addressing ........................................................................................... 42 User LED Control ......................................................................................... 45 Processor Ethernet Signals............................................................................ 47 EEPROM Contents ....................................................................................... 52 Expansion Header P8 Pinout ........................................................................ 54 P8 Mux Options Modes 0-3 .......................................................................... 55 P8 Mux Options Modes 4-7 .......................................................................... 57 Expansion Header P9 Pinout ........................................................................ 59 P9 Mux Options Modes 0-3 ......................................................................... 60 P9 Mux Options Modes 4-7 ......................................................................... 62 Expansion Board EEPROM .......................................................................... 68 EEPROM Pin Usage ..................................................................................... 69 Page 9 of 83 REF: BBONE_SRM Table 16. Table 17. Table 18. Table 19. Table 20. BeagleBone System Reference Manual RevA5.0.1 Single Cape Connectors ................................................................................ 73 Single Cape Backlight Connectors ............................................................... 74 Stacked Cape Connectors ............................................................................. 75 Stacked Cape Connectors ............................................................................. 75 Expansion Voltages ...................................................................................... 76 Page 10 of 83 REF: BBONE_SRM 1.0 BeagleBone System Reference Manual RevA5.0.1 Introduction This document is the System Reference Manual for the BeagleBone. It covers revision A3 and revision A4. It is intended as a guide to assist anyone purchasing or who are considering purchasing the board to understand the overall system design and the features of the BeagleBone. It can also be used as a reference for the design for those who are implementing this design into their own product. This design is subject to change without notice as we will work to keep improving the design as the product matures. 2.0 Change History 2.1 Change History Table 1. Rev 0.1 0.2 A4.0.4 Change History Changes Original Release for review 1. 2. 3. 4. 1. 2. 3. 4. 5. 6. 1. 2. 3. A5 4. 5. 6. 7. 1. A5.0.1 2. Added notch dimension to the Cape board outline. Added power numbers to features table. Corrected USB0 and USB1 numbering Made correction on two signals on Tables 10 thru 12. Rev A4 Release Documented the changes. Updated Figure 28 to show pullup resistors as 5.6K. Added note to Cape section that mounting holes are not required. Fixed link to the TPS65217B documentation. Added section on ADC interface. Added clarification on image creation process. Added more detail on USB 5VDC supplied to Capes. Corrected section 6.3.6 to reflect four UART ports instead of five. Updated Figure 36 with more hole dimensions. Added section on the rev A4 to Rev A5 changes. Made changes in Table 12. Added note on polarity of Yellow Ethernet LED in section 7.8.7. Corrected dropout voltage on the TPS65217B LDOs in section 7.13.6. Corrected Table 15 to show correct connector number son AIN06. Page 11 of 83 Date By November 4, 2011 GC November 11, 2011 GC January 3, 2012 January 31, 2012 February 13, 2012 GC GC GC REF: BBONE_SRM 2.2 BeagleBone System Reference Manual RevA5.0.1 Rev A4 vs. A5 There was a key issue with rev A4 where R219 was causing some unintended issues with the operation of the Ethernet interface. 2.2.1 PCB Changes There were no PCB changes. 2.2.2 Design Changes 1) R219 was removed from the assembly. It will be reinstated at Rev A6 with a PCB change. 2.2.3 Production Changes 1) Changes were made in production testing to test for bad Reset switches 2) Reset switches are not being taken through the wash. 3) The FTDI VID was changed to 0403 and the PID was changed to 6010. Description was changed to “BeagleBone/XDS100” This version of the board returns the functionality of the board to that of the Rev A3 via the removal of R219. It uses the same PCB revision as the A4. It also ships with an updated version of the Angstrom image providing out of the box support for the DVI-D and 7” LCD Capes. There will be three possible versions of the Rev A5. One will be the new production version that is built from the ground up as an A5, R219 not installed. The second version will be a reworked Revision A4 that has R219 removed at the factory and retested. The third version will be a revision A3 that just has the updated SW added. All reworked versions will have the reset switches double checked as well. All reworked boards will be retested using the full production test process. You will be able to identify these versions via the serial number. They all will be labeled as revision A5. The two digits after the BB in the serial number, S/N: 5111BB000023, will indicate the board. A fresh revision A5, will be 00, A4 reworked will be 01, and a recertified A3 will be 02. There is no functional or operational difference between any of these boards. They are all revision A5 and will ship with the same SW. For those with Revision A3 and A4, you will be able to download the latest shipping image from http://circuitco.com/support/index.php?title=BeagleBone and have all the features of the Revision A5. For A4 users, you will need to remove R219 and instructions are provided at http://circuitco.com/support/index.php?title=BeagleBone . Page 12 of 83 REF: BBONE_SRM 2.3 BeagleBone System Reference Manual RevA5.0.1 Rev A3 vs. A4 No functional changes were made to the board as it relates to its overall operation. 2.3.1 PCB Changes The following PCB changes were made to facilitate the acquisition of components to meet the production schedule which required different footprints. • • • 2.3.2 New microSD connector. PCB layout was changed to facilitate the change. 50 ohm resistor was changed to a 0402 footprint. Changes C7 footprint to 0805. Design Changes Added a 10k pull down resistor, R219, to fix polarity of the speed LED on the Ethernet connector. NOTE: The pictures in this document were not changed to reflect the new A4 version. The benefit of doing this is very small. The only obvious difference is the big resistor below the USB Host connector is no longer there. Page 13 of 83 REF: BBONE_SRM 3.0 BeagleBone System Reference Manual RevA5.0.1 BeagleBone Overview The BeagleBone is the latest addition to the BeagleBoard.org family and like its’ predecessors, is designed to address the Open Source Community, early adopters, and anyone interested in a low cost ARM Cortex A8 based processor. It has been equipped with a minimum set of features to allow the user to experience the power of the processor and is not intended as a full development platform as many of the features and interfaces supplied by the processor are not accessible from the BeagleBone via onboard support of some interfaces. 3.1 BeagleBone Expansion By utilizing comprehensive expansion connectors, the BeagleBone is highly extensible to add many features and interfaces via add-on boards or Capes. Capes refer to the shape of the add-on boards and are discussed later in this document. A majority of the signals from the processor are exposed via the expansion headers and can be accessed there, but may require additional hardware in order to use them. This will be handled by the creation of Capes in the future. Due to the deep multiplexing of the pins, there are limits as to how many interfaces can coexist at any one time. Refer to the processor documentation for more information. 3.2 BeagleBone Design Material All of the design information is freely available and can be used as the basis for a product or design. If the user decides to use the BeagleBone design in a product, they assume all responsibility for such use and are totally responsible for all aspects of its use. We do not sell BeagleBone boards for use in end products. We choose to utilize our resources to create boards for the expressed purpose as previously stated. We will be changing the design to improve it and will not continue to make older revisions as the overall design matures. There are programs available for someone to have the board built to their specifications and then use that board in a product. All of the design information is freely available and will be kept up to date. Anyone is free to use that information as previously stated. 3.3 In The Box The BeagleBone ships in a box with the following components: • • • BeagleBone USB Cable 4GB uSD card with SW and documentation Page 14 of 83 REF: BBONE_SRM 4.0 BeagleBone System Reference Manual RevA5.0.1 BeagleBone Features and Specification This section covers the specifications and features of the BeagleBone and provides a high level description of the major components and interfaces that make up the BeagleBone. Table 2 provides a list of the BeagleBone’s features. Table 2. BeagleBone Features Feature Processor Memory PMIC TPS65217B Debug Support Power PCB AM3359 500MHZ-USB Powered 720MHZ-DC Powered 256MB DDR2 400MHZ (128MB Optional) Power Regulators LiION Single cell battery charger (via expansion*) 20mA LED Backlight driver, 39V, PWM (via expansion*) *(Additional components required) miniUSB connector USB to Serial Adapter On Board JTAG via USB 4 USER LEDs Optional 20-pin CTI JTAG 5VDC External jack USB 6 layers 3.4” x 2.1” HS USB 2.0 Client Port Power 4-User Controllable LEDs Access to the USB1 Client mode HS USB 2.0 Host Port USB Type A Socket, 500mA LS/FS/HS Ethernet SD/MMC Connector User Interface Overvoltage Protection 5V Power 10/100, RJ45 microSD , 3.3V 1-Reset Button Shutdown @ 5.6V MAX Power 5V, 3.3V , VDD_ADC(1.8V) 3.3V I/O on all signals McASP0, SPI1, I2C, GPIO(65), LCD, GPMC, MMC1, MMC2, 7 AIN(1.8V MAX), 4 Timers, 3 Serial Ports, CAN0, EHRPWM(0,2),XDMA Interrupt, Power button, Battery Charger, LED Backlight, Expansion Board ID (Up to 3 can be stacked) USB or 5.0VDC to 5.2VDC See Table 3 for power consumption numbers. Weight 1.4 oz (39.68 grams) Indicators Expansion Connectors *Board will boot to 500MHz under USB power. NOTE: DUE TO MULIPLEXING ON THE PINS OF THE PROCESSOR, ALL OF THESE EXPANSION SIGNALS CANNOT BE AVAILABLE AT THE SAME TIME. NOTE: The battery configuration is not suitable to power the BeagleBone in its current configuration. The following sections provide more detail on each feature and sections of the board. Page 15 of 83 REF: BBONE_SRM 4.1 BeagleBone System Reference Manual RevA5.0.1 Board Component Locations The Figure 1 below shows the top side locations of the key components on the PCB layout of the BeagleBone. Figure 1. Top Side Components Figure 2 shows the key components mounted on the back side of the board. Page 16 of 83 REF: BBONE_SRM BeagleBone System Reference Manual 7 Figure 2. Bottom Side Components Page 17 of 83 RevA5.0.1 REF: BBONE_SRM 4.2 BeagleBone System Reference Manual RevA5.0.1 Board Connector and Indicator Locations Figure 3 shows the key connector and LED locations of the BeagleBone. Figure 3. Board Connector and Indicators NOTE: Be careful if you are considering using standoffs on the BeagleBone. The mounting hole next to the DC power jack has resistors that are a little too close to the hole and if you are not careful, you can damage those resistors when attaching the standoff. Use as small a diameter standoff as possible. Page 18 of 83 REF: BBONE_SRM BeagleBone System Reference Manual Page 19 of 83 RevA5.0.1 REF: BBONE_SRM 5.0 BeagleBone System Reference Manual RevA5.0.1 BeagleBone Design Specification This section provides a high level description of the design of the BeagleBone. 5.1 Processor The board currently uses the AM3359 processor in the 15x15 package. Actual processor speed will be determined by the actual devices supplied. The board is being released prior to the processor being in full production and as a result, has the AM3359 due to availability of those parts at this time. When changed to the AM3358, no loss of features will be experienced. 5.2 Memory As single x16 bit DDR2 memory device is used. The design supports 128MB or 256MB of memory. The standard configuration is 256MB at 400MHz. A 128MB version may be built later, but there are no definite plans for this. A single 32KB EEPROM is provided on I2C0 that holds the board information. This information includes board name, serial number, and revision information. Unused areas can be used by SW applications if desired. 5.3 Power Management The TPS65127B power management device is used along with a separate LDO to provide power to the system. 5.4 PC USB Interface The board will have an onboard USB HUB that concentrates two USB ports used on the board to one to facilitate the use of a single USB connector and cable to the PC. Support via this HUB includes: • • • USB to serial debug USB to JTAG USB processor port access When connected to the PC each of these will show up as ports on the PC. Page 20 of 83 REF: BBONE_SRM 5.4.1 BeagleBone System Reference Manual RevA5.0.1 Serial Debug Port Serial debug is provided via UART0 on the processor using a dual channel FT2232H USB to serial device from FTDI to connect these signals to the USB port. Serial signals include Tx, Rx, RTS, and CTS. A single EEPROM is provided on the FT2232H to allow for the programming of the vendor information so that when connected, the board can be identified and the appropriate driver installed. 5.4.2 JTAG Port The second port on the FT2232H will be used for the JTAG port. Direct connection to the processor is made from the FT2232H. There is a JTAG header provided on the board as an option, but it is not populated. 5.4.3 USB0 Port The HUB connects direct to the USB0 port on the processor. This allows that port to be accessible from the same USB connector as the Serial and JTAG ports. 5.5 MicroSD Connector The board is equipped with a single microSD connector to act as the primary boot source for the board. A 4GB microSD card is supplied with each board. The connector will support larger capacity SD cards. 5.6 USB1 Port On the board is a single USB Type A connector with full LS/FS/HS Host support that connects to USB1 on the processor. The port can provide power on/off control and up to 500mA of current at 5V. Under USB power, the board will not be able to supply the full 500mA, but should be sufficient to supply enough current for a lower power USB device. You can use a wireless keyboard/mouse configuration or you can add a HUB for standard keyboard and mouse interfacing if required. 5.7 USB Client Port Access to USB0 is provided via the onboard USB Hub. It will show up on a PC as a standard USB device. Page 21 of 83 REF: BBONE_SRM 5.8 BeagleBone System Reference Manual RevA5.0.1 Power Sources The board can be powered from a USB port on a PC or from an optional 5VDC power supply. The power supply is not provided with the board and must be a grounded power supply. The USB cable is shipped with the board. When powered from USB, the board is limited to 500 MHz. The onboard HUB + FT2232H power consumption does not leave room in the 500mA budget for the boot process. For 720 MHz operation, DC power is required. The lowest power mode is DC w/o the USB port connected, even at 720MHz. Power can be supplied via a 2.1mm x 5.5mm center connector when connected to a positive power supply rated at 5VDC +/- .1V and 1A. This is similar to the power supply as currently used on BeagleBoards and the board can be powered from a supply that was used to power the BeagleBoard. Do not apply voltages in excess of 5V to the DC input. The DC power supply must be grounded. 5.9 Reset Button When pressed and released, causes a reset of the board. Due to the small size of the switch, you will not experience a lot of travel when pushing the switch. 5.10 Indicators There are five total green LEDs on the board. Four can be controlled by the user and one static LED. o One power LED indicates that power is applied. o Four Green LEDs that can be controlled via the SW by setting GPIO ports. 5.11 CTI JTAG Header An optional 20 pin CTI JTAG header can be provided on the board to facilitate the SW development and debugging of the board by using various JTAG emulators. In order to use the connector, series resistors must be removed to isolate the USB to JTAG feature. This header is not supplied standard on the board and the typical user will not be able to make the resistor changes. Page 22 of 83 REF: BBONE_SRM 6.0 BeagleBone System Reference Manual RevA5.0.1 Expansion Interface This section describes the expansion interface and the features and functions available from the expansion header. 6.1 Main Board Expansion Header Two 46 pin dual row .1 x .1 female headers are supplied on the board for access to the expansion signals. Due to the number of pins, a low insertion force header has been chosen to facilitate the removal of the Capes. However, due to the large number of pins, removal can be difficult and care should be taken in the removal of the boards connected to the expansion headers. Figure 4 below is a picture of the female header used. Figure 4. 6.2 Main Board Expansion Connector Cape Expansion Boards Each expansion board or Cape will have 2 46 pin connectors. Their exact type and configuration will vary depending on the method used. Refer to Section 8 for more details. The connectors used will be thruhole connectors. Up to four Capes can be stacked onto the BeagleBone. Each board will have the same EEPROM as is found on the main board but will be at different addresses to allow for scanning for expansion boards via the I2C bus. Each board will be equipped with a 2 position dipswitch to set the address of the board based on the stack position. It is up to the user to insure the proper setting of this dipswitch to prevent a conflict on the I2C bus. Page 23 of 83 REF: BBONE_SRM BeagleBone System Reference Manual RevA5.0.1 Standard expansion board size is 3.4” x 2.1”. The board will have a notch in it to act as a key to insure proper orientation. The key is around the Ethernet connector on the main board. Oversize boards, such as LCD panels, are allowed. The main board will extend out from under these boards. 6.3 Exposed Functions This section covers functionality that is accessible from the expansion header. NOTE: Not all functionality is available at the same time due to the extensive pin muxing of the signals on the processor. Please refer to the processor documentation for detailed information on the uses and functions of the pins listed in the following sections. 6.3.1 LCD A full 24 bit LCD panel can be supported. With the main board having backlight and touchscreen functionality, will simply and lower the cost of LCD expansion boards. Backlight power is limited to 25mA, so this may not be enough for larger panels. If other functions are needed on an expansion board, such as NAND support, the full 24 bit display may not be able to be supported due to the pin muxing. You can also create 16 bit LCD boards. The advantage here is that this uses fewer pins on the expansion connectors leaving more signals to be used by other expansion boards. 6.3.2 GPMC Access to the GPMC bus is provided. Depending on the configuration needed, this may result in the loss of the LCD interface. Support for a 16 bit wide NAND is provided by the expansion board. This will limit the LCD display to 16Bits. Make sure you review and understand the pin muxing option before doing a design. 6.3.3 MMC1 MMC1 signals are exposed on the expansion headers. 6.3.4 SPI There are two SPI ports available on the expansion header. SPIO0 has one CS and SPI1 has two CS signals. Page 24 of 83 REF: BBONE_SRM 6.3.5 BeagleBone System Reference Manual RevA5.0.1 I2C There are two I2C Ports on the expansion header, I2C1 and I2C2. I2C2 is used for the EEPROMS on the expansion boards and must always be accessible. SW should never mess with these signals. Other components on a Cape can use this bus as long as it does not conflict with the base addresses of the Capes. 6.3.6 Serial Ports There are four serial ports on the expansion headers. UART ports 1, 2, 4 ports have TX,Rx,RTS and CTS signals while UART5 only has TX and RX. 6.3.7 A/D Converters Seven 100K sample per second A to D converters are available on the expansion header. NOTE: Maximum voltage is 1.8V. Do not exceed this voltage. Voltage dividers should be used for voltages higher than 1.8V. In order to use these signals, level shifters will be required. These signals connect direct to the processor and care should be taken not to exceed this voltage. The VDD_ADC voltage is 1.8V and is not to be used to power anything. It is only a reference voltage and should be used to set the reference level for those interfaces added to the CAPE and not used to supply power. 6.3.8 GPIO A maximum of 66 GPIO pins are accessible from the expansion header. All of these pins are 3.3V and can be configured as inputs or outputs. Any GPIO can be used as an interrupt and is limited to two interrupts per GPIO Bank for a maximum of eight pins as interrupts. 6.3.9 CAN Bus There are two can bus interfaces available on the expansion header supporting CAN version 2 parts A and B. The TX and RX digital signals are provided. The drivers and connectors will need to be provided on a daughter card for use. 6.3.10 TIMERS There are four timer outputs on the expansion header. Page 25 of 83 REF: BBONE_SRM BeagleBone System Reference Manual 6.3.11 PWM There are up to eight PWM outputs on the expansion header. • • High Resolution Outputs- up to 6 single ended. ECAP PWM- 2 outputs Page 26 of 83 RevA5.0.1 BeagleBone System Reference Manual REF: BBONE_SRM 7.0 RevA5.0.1 Detailed Board Design This section describes the detailed design of the BeagleBone. Please be sure to reference the AM3359 datasheet and technical reference manual to gain a deeper understanding. 7.1 System Block Diagram Figure 5 is the high level system block diagram of the BeagleBone. Figure 5. System Block Diagram Each of these sections is discussed in more detail in the following sections. 7.2 Processor The board is designed to use the AM3358 processor in the 15 x 15 package. Initial boards that ship will have the AM3359 processor as that is the version that is currently available. Page 27 of 83 REF: BBONE_SRM 7.2.1 BeagleBone System Reference Manual RevA5.0.1 Processor Block Diagram Figure 6 is a high level block diagram of the processor. For more information on the processor, go to http://www.ti.com/product/am3359 Figure 6. Processor Block Diagram Page 28 of 83 REF: BBONE_SRM 7.3 BeagleBone System Reference Manual RevA5.0.1 System Power Figure 7 is a high level block diagram of the power section design of the BeagleBone. Figure 7. 7.3.1 Power Subsection Block Diagram TPS65217B PMIC The main Power Management IC (PMIC) in the system is the TPS65217B. The TPS65217B is a single chip power management IC consisting of a linear dual-input power path, three step-down converters, four LDOs, and a high-efficiency boost converter to power two strings of up to 10 LEDs in series. The system is supplied by a USB port or DC adapter. Three high-efficiency 2.25MHz step-down converters are targeted at providing the core voltage, MPU, and memory voltage for the board. The step-down converters enter a low power mode at light load for maximum efficiency across the widest possible range of load currents. For low-noise applications the devices Page 29 of 83 REF: BBONE_SRM BeagleBone System Reference Manual RevA5.0.1 can be forced into fixed frequency PWM using the I2C interface. The step-down converters allow the use of small inductors and capacitors to achieve a small solution size. LDO1 and LDO2 are intended to support system-standby mode. In SLEEP state output current is limited to 100uA to reduce quiescent current whereas in normal operation they can support up to 100mA each. LDO3 and LDO4 can support up to 285mA each. By default only LDO1 is always ON but any rail can be configured to remain up in SLEEP state. Especially the DCDC converters can remain up in a low-power PFM mode to support processor Suspend mode. The TPS65217B offers flexible power-up and power-down sequencing and several house-keeping functions such as power-good output, pushbutton monitor, hardware reset function and temperature sensor to protect the battery. For more information on the TPS65217B, refer to http://www.ti.com/product/tps65217b . Figure 8 is the high level block diagram of the TPS65217B. Page 30 of 83 REF: BBONE_SRM Figure 8. BeagleBone System Reference Manual TPS65217B Block Diagram Page 31 of 83 RevA5.0.1 BeagleBone System Reference Manual REF: BBONE_SRM 7.3.2 RevA5.0.1 5V DC Power Input Figure 9 is the design of the 5V DC input circuit to the TPS65217B. VDD_5V SY S_5V U1 1 3 2 1 7 1 3 6 2 OUT1 OUT0 EN FLAG 2 PJ-200A IN0 IN1 GND P5 U2 5 4 10 DC_IN AC SY S1 SY S2 7 8 3 NCP349 DGND C1 TPS65217B 4.7uF,6.3V DGND DGND Figure 9. 5V DC Power Input A 5VDC supply can be used to provide power to the board. The power supply current depends on how many and what type of add on boards are connected to the board. For typical use, a 5VDC supply rated at 1A should be sufficient. If heavier use of the expansion headers or USB host port is expected, then a higher current supply will be required. The connector used is a 2.1MM center positive x 5.5mm outer barrel. A NCP349 over voltage device is used to prevent the plugging in of 7 to 12 V power supplies by mistake. The NCP349 will shut down and the board will not power on. No visible indicator is provided to indicate that an over voltage condition exists. The board will not power up. The 5VDC rail is connected to the expansion header. It is possible to power the board via the expansion headers from a add-on card. The 5VDC is also available for use by the add-on cards when the power is supplied by the 5VDC jack on the board. 7.3.3 USB Power The board can also be powered from the USB port. A typical USB port is limited to 500mA max. When powering from the USB port, the VDD_5V rail is not provided to the expansion header. So Capes that require that rail will not have that rail available for use. The 5VDC supply from the USB port is provided on the SYS_5V rail of the expansion header for use by a Cape. Figure 10 is the design of the USB power input section. Page 32 of 83 BeagleBone System Reference Manual RevA5.0.1 9 G4 5 4 3 2 1 SY S_5V U2 12 G2 G1 ID D+ DVB 7 mini USB-B 6 G3 G5 8 REF: BBONE_SRM P3 DC SYS1 SYS2 7 8 DGND C2 4.7uF,6.3V TPS65217B DGND Figure 10. USB Power Input 7.3.1 Power Source Selection The selection of either the 5VDC or the USB as the power source is handled internally to the TPS65217B and automatically switches to 5VDC power if both are connected. SW can change the power configuration via the I2C interface from the processor. In addition, the SW can read the TPS65217B and determine if the board is running on the 5VDC input or the USB input. This can be beneficial to know the capability of the board to supply current for things like operating frequency and expansion cards. It is possible to power the board from the USB input and then connect the DC power supply. The board will switch over automatically to the DC input. 7.3.2 Power Consumption The power consumption of the board varies based on power scenarios and the board boot processes. Table 3 is an analysis of the power consumption of the board in these various scenarios. Table 3. BeagleBone Power Consumption(mA@5V) MODE Reset UBoot Kernel Booting (Peak) Kernel Idling USB 180 363 502 DC 60 230 350 DC+USB 190 340 470 305 170 290 When the USB is connected, the FT2232 and HUB are powered up. This causes an increase in current. When the USB is not connected, these devices are in a lower power state. This is accounts for roughly 120mA of current and is the reason for the increased current when the USB is connected. Page 33 of 83 BeagleBone System Reference Manual REF: BBONE_SRM RevA5.0.1 The current will fluctuate as various activates occur, such as the LEDs on and SD card accesses. 7.3.3 Power Sequencing The power up process is made up of several stages and events. Figure 11 is the events that make up the power up process of the system. Figure 11. Power Sequencing 7.3.4 TPS65217B Power Up When voltage is applied, DC or USB, the TPS65217B connects the power to the SYS output pin which drives the switchers and LDOS in the TP65217B. At power up all switchers and LDOs are off except for the VRTC LDO (1.8V), provides power to the VRTC rail. Once the RTC rail powers up, the RTC_PORZ pin of the processor can be release. Figure 12 is the circuit that controls the RTC_PORZ pin. Page 34 of 83 BeagleBone System Reference Manual REF: BBONE_SRM RevA5.0.1 VRTC C21 VRTC 1 8 DGND 7 2 VRTC_DET 1.1K,1% R17 SN74AUP2G08 5 VRTC_DETB 6 4 SN74AUP2G08 C22 0.01uf ,16V DGND R141 U17B 10K,1% LDO_PGOOD 2 R143 3 VRTC_DET_OUT RTC_PORZ 0,1%,DNI 4 8 0.01uf ,16V U17A R18 DGND 12.1K,1% DGND DGND Figure 12. RTC_PORZ Control There are actually two circuits in this design. One uses a pair of AND gates to create the RTC_PORZ signal and the other uses the LDO_PGOOD signal form the TPS65217B. In the case of the AND gate circuit, once the VRTC rail comes up the circuit delays the RTC_PORZ which releases the RTC circuitry in the processor. In the case of the LDO_PGOOD signal, it is provided by the TPS65217B. As this signal is 3.3V and the RTC_PORZ signal is 1.8V, a voltage divider is used. Once the LDOs are up on the TPS65217B, this signal goes active. The LDOs on the TPS65217B are used to power the VRTC rail on the processor. The LDO_PGOOD version the default circuit currently used on the A3 design. It is possible on future revisions that the AND gate circuitry will be removed from the design. Once the RTC block reset is released, the processor starts the initialization process. After the RTC stabilizes, the processor launches the rest of the power up process by activating the PMIC_PWR_EN signal. This starts the TPS65217B power up process. A separate signal, PMIC_PGOOD, holds the processor reset for 20ms after all power rails are up. 7.3.5 Voltage Rails There are seven voltages supplied by the TPS65217B. Each of these are described in the following sections. 7.3.5.1 VDD_1V8 VDD_1V8 defaults to 1.8V on power up. The TPS65217B can deliver up to 1200mA on this rail. This rail only connects to the processor and the DDR2 memory. Page 35 of 83 REF: BBONE_SRM 7.3.5.2 BeagleBone System Reference Manual RevA5.0.1 VDD_MPU VDD_MPU defaults to 1.1V on power up. This voltage can be changed under software control up to 1.25V in order to support higher processor frequencies. The TPS65217B can deliver up to 1200mA on this rail. This rail only connects to the processor. 7.3.5.3 VDD_CORE VDD_CORE defaults to 1.1V on power up. This voltage should always be left at 1.1V. The TPS65217B can deliver up to 1200mA on this rail. This rail only connects to the processor. 7.3.5.4 VDD_3V3A VDD_3V3A is the first of two 3.3V rails on the TPS65217B. The TPS65217B can deliver up to 225mA on this rail. This rail connects to the processor I/O rail voltage, TPS65217B I/O rail, and the SD/MMC card. 7.3.5.5 VDD_3V3B VDD_3V3B is the second of two 3.3V rails on the TPS65217B. The TPS65217B can deliver up to 225 mA on this rail. This rail connects to the LAN8710, EEPROM, USB2412HUB, and FT2232. 7.3.5.6 VRTC VRTC is the first rail to turn on during power up and is a 1.8V rail. The TPS65217B can deliver up to 100mA on this rail. This rail connects to the processor. 7.3.5.7 VLDO2 VLDO2 is a 3.3V rail that drives the power LED. This can be turned off via SW if a low current mode for the board, such as standby, is required. 7.3.6 Power Indicator LED The board has a single power indicator LED. It is controlled via 3.3V VLDO2 power rail on the TPS65217B. When the TPS65217B has initialized and all switchers are on, the VLDO2 rail is activated turning on the LED. If the switchers are not initialized, for example if the processor does not enable the PWR_EN signal, the LED will not turn on. Page 36 of 83 BeagleBone System Reference Manual REF: BBONE_SRM RevA5.0.1 The power LED indicates that the TPS65217B is powered up. It is possible for the SW to turn off this rail to conserve power. 7.3.7 Expansion 3.3V LDO A separate LDO provides the 3.3V rail to the expansion headers. Figure 13 below is the design of the LDO. VDD_3V3A SY S_VOLT VDD_3V3EXP U8 8 2 5 9 4 C6 4.7uF,6.3V IN NC1 EN PAD GND OUT NC2 NC3 FB 1 6 7 3 3V3EXP_FB R189 TPS73701DRBR DGND R150 52.3K,1% C166 0.1uf ,16V 30.1K,1% DGND Figure 13. Expansion 3.3V Regulator U8 is a TPS73710 adjustable regulator that creates the 3.3V for the expansion bus by the values of R150 and R189. The allowable current for this rail is set to 500mA based on the design of the PCB, but that depends upon the total amount of current available from the main input supply. 7.4 Current Measurement The BeagleBone has a method under which the current consumption of the board, not counting the USB Host port and expansion boards, can be measured. The voltage drop across a .1 ohm resistor is measured to determine the current consumption. Figure 14 shows the interface to the TPS65217B to measure the current. The following sections describe this circuitry in more detail. 7.4.1 SYS_5V Connection The SYS_5V rail is measured to determine the high side of the series resistor. The SYS_5V rail is connected to the MUX_OUT pin. Prior to being connected to the internal second multiplexer, the voltage is divided by 3. A 5V signal will result in a voltage of 1.66V at the MUX_OUT pin. Page 37 of 83 BeagleBone System Reference Manual REF: BBONE_SRM RevA5.0.1 Figure 14. Current Measurement 7.4.2 SYS_VOLT Connection The SYS_VOLT rail is measured to determine the high side of the series resistor. The SYS_VOLT rail is connected to the MUX_OUT by setting the registers inside the TPS65217B. The resistors R2 and R1 are provided to keep the same voltage divider configuration as found in the SYS_5V rail located internal to the TPS65217B. However, a 5V rail will give you 1.41V as opposed to the 1.66V found internal to the TPS65217B. This works out to a devisor of 2.8. Be sure and work this into your final calculations. 7.4.3 MUX_OUT Connection The MUX_OUT connection is divided by 2 before being connected to the processor. The reason for this is that if the battery voltage is connected, it has no voltage divider internally. If connected it could damage the processor. When calculating the voltages for either side of the resistors, that voltage is divided by 2. Be sure and include this in your calculations. 7.4.4 Current Calculation The calculation for the current is based on .1mV is equal to 1mA. You can use the following formula to calculate the current using the voltage readings as read by the processor. (((SYS_5V*2)*3.3)-((SYS_VOLT*2)*3.54)))/.1=Total mA. 7.5 Two Port USB HUB Page 38 of 83 BeagleBone System Reference Manual REF: BBONE_SRM RevA5.0.1 In order to provide access from a single USB port to the FT2232 and the processor USB port, a SMSC USB2412 dual port USB 2.0 HUB is provided. This device connects to the host PC. Figure 15 is the design of the USB HUB. Upstream 18 VBUS_DET USBDP_UP USBDM_UP 22 21 G1 ID D+ DVB Dow nstream 1USBDP_DN1 8 DGND USBDM_DN1 OCS1 PRTPWR1 DGND 1 28 7 FT_DP 10 FT_DM 10 FT_VBUS 10 P3 7 R151 100K,1% G5 G4 9 USBDP_UP USBDM_DN G2 VBUS_DET 5 4 3 2 1 USB2412_QFN28 USB_DC G3 U11 mini USB-B 6 USB_DC R149 100K,1% 8 USB_DC R152 4.75K,1% U16B 3 Dow nstreamUSBDP_DN2 2 12 OCS2 USBDM_DN2 PRTPWR2 VDD_3V3B NON_REM[0:1]/nc NON_REM1 SUSP_IND/NON_REM0 R156 100K,1% 17 RESETn 6 C136 0.1uf ,16V DGND DGND C137 3 R160 Y5 4 RESET RBIAS 11 USB0_DM 24 R154 10K,1%,DNI 13 19 NON_REM1 NON_REM2 26 HUB_BIAS R157 2 12.1K,1% DGND DGND DGND R155 10K,1%,DNI R158 R159 10K,1% 100K,1% 14 10 4 20 27 4 TP7 C139 DGND TESTPT1 DGND C140 0.1uf ,16V4.7uF,6.3V VDD33 VDD33 VDDPLLREF/VDD33 USB0_VBUS VDD_3V3B USB0_VBUS_PWR XTALIN/CLKIN 24MHz 4 VDD_3V3B VDD33 VDDCRREF/VDD33 4 SN74LVC2G07DCK 4 5 Common TEST USB0_DP 2 C138 XTALIN 18pF,50V NC 3 0.1uf ,16V DGND 1M,1%,DNI XTALOUT 23 HS_IND 16 TP8 18pF,50V DGND C141 0.1uf ,16V 1 C144 TESTPT1 rsv d3 0,1% R161 15 29 C142 0.1uf ,16V C143 0.1uf ,16V XTALOUT CRFILT HS_IND 9 CRFILT DGND VSS PLLFILT 25 PLLFILT C145 VSS(FLAG) 0.1uf ,10V,DNI C146 0.1uf ,10V,DNI DGND DGND DGND Figure 15. USB HUB Design 7.5.1 Processor USB Port The USB connection to the host is via a mini USB connector. The power from this connector is connected to the TPS65217B to allow the board to be powered from the USB Host port. The signal pins connect to the USB HUB. 7.5.2 HUB Power The HUB is powered from the 3.3VB rail from the TPS65217B. The HUB will remain in a low power mode until the USB port is connected. The USB2412 monitors the VBUS_DET pin for logic high when the USB 5V supply is detected. 7.5.3 Crystal and Reset Page 39 of 83 REF: BBONE_SRM BeagleBone System Reference Manual RevA5.0.1 The USB2412 uses a single 24MHZ crystal. The RESET signal is self generated from the VDD_3V3B rail to an RC network. 7.5.4 FT2232H Serial Adapter The first port of the HUB connected to the FT2232 which handles the processor serial port and JTAG and is described in the next section. The DP and DM signals from the USB2412 connect direct to the FT2232H. The FT_BUS signal is used by the FT2232H to detect the presence of the host USB port. Once the HUB is connected to the Host, this pin will go HI to indicate the presence of the USB port. 7.5.5 Processor USB Port The second port of the HUB is connected to the processor USB port 0. In order for the port to work on the processor it must first detect the presence of 5V on the VBUS pin. The USB2412 puts out a 3.3V signal on the PRTPWR2 so U16 converts that signal to a 5V logic level as required by the processor. Page 40 of 83 BeagleBone System Reference Manual REF: BBONE_SRM 7.6 RevA5.0.1 FT2232H USB to Serial Adapter The FT2232H from FTDI provides the conversion from the USB port to the JTAG interface and Serial port to the processor. Figure 16 is the design of the FT2232H circuit. VDD_3V3B VDD_3V3B 2 FB7 VDD_FTVPHY 2 FB8 U12 50 VDD_1V8FT 49 VREGIN VREGOUT ADBUS0 ADBUS1 ADBUS2 ADBUS3 ADBUS4 ADBUS5 ADBUS6 ADBUS7 DGND 9 9 12.1K,1% FT_REF R167 6 7 8 FT_DM FT_DP XTIN C153 27pF,50V DGND 2 REF USBDM USBDP ACBUS0 ACBUS1 ACBUS2 ACBUS3 ACBUS4 ACBUS5 ACBUS6 ACBUS7 OSCIN Y6 12.000MHz 50ppm VDD_3V3B R174 R173 U13 6 2 VCC 5 4 3 1 FT_RESETn 2.2K,1% 93LC56B_SOT23-6 DGND 3 14 63 62 61 F_EECS F_EESK F_EEDATA F_EEDOUT GND R175 10K,1% 10K,1% CS SK DIN DOUT XTOUT C155 27pF,50V DGND 13 BDBUS0 BDBUS1 BDBUS2 BDBUS3 BDBUS4 BDBUS5 BDBUS6 BDBUS7 OSC0 RESET BCBUS0 BCBUS1 BCBUS2 BCBUS3 BCBUS4 BCBUS5 BCBUS6 BCBUS7 EECS EECLK EEDATA GND8 GND7 GND6 GND5 GND4 GND3 GND2 GND1 AGND DGND 1 5 11 15 25 35 47 51 2.2K,1% 10 10K,1% C150 0.1uf ,16V C151 0.1uf ,16V DGND VDD_3V3B 16 17 18 19 21 22 23 24 F_ADBUS0 F_ADBUS1 F_ADBUS2 F_ADBUS3 F_ADBUS4 R164 R165 R166 R168 R169 0,1% 0,1% 0,1% 0,1% 0,1% F_ADBUS6 R170 0,1% 26 27 28 29 30 32 33 34 F_ADBUS5 38 39 40 41 43 44 45 46 48 52 53 54 55 57 58 59 R172 F_ADBUS7 0,1% R171 UART0_TX UART0_RX UART0_CTS UART0_RTS 0,1% 4 4 4 4 DGND VDD_3V3B R181 10K,1%,DNI FT_VBUS 9 TEST PWREN R188 R187 0.1uf ,16V C164 0.1uf ,16V 0.1uf ,16V0.1uf ,16V DGND C148 20 31 42 56 C163 C147 0.1uf ,16V VDD_FTREGIN VCCIOA VCCIOB VCCIOB VCCIOD 4.7uF,6.3V 2 FB6 VDD_FTVPLL 12 37 64 C162 DGND VCOREC VCOREB VCOREA C152 0.1uf ,16V 4 9 1 150OHM800mA 1 150OHM800mA 0.1uf ,16V C158 VPHY VPLL 1 150OHM800mA C161 SUSPEND 60 36 FT2232LQFN64 DGND Figure 16. FT2232H Design 7.6.1 EEPROM U13 is a EEPROM that tells U12 the configuration of the device and the I/O pins. In order for the FT2232H to operate properly, this device must be programmed. Using the tools provided by FTDI makes this process straight forward. Page 41 of 83 BeagleBone System Reference Manual REF: BBONE_SRM 7.6.2 RevA5.0.1 JTAG Using a parallel I/O mode, the FT2232H can be used to access the JTAG signals on the processor. At USB 2.0 speeds, the throughput is very good, and should provide connectivity to several popular debug environments including Code Composer Studio 7.6.3 Serial Port Access to UART0 is provided by the FT2232H via the USB port. Signals available are TX, RX, RTS, and CTS. 7.7 256MB DDR2 Memory The board comes standard with 256MB DDR SDRAM configured as a single 128M x 16 device. The design will also support a single 64M x 16 device for 128MB of memory. The memory size cannot be extended past 256MB. The design uses a single MT47H128M16RT-25E:C 400MHZ memory from Micron which comes in an 84-Ball 9.0mm x 12.5mm FBGA package. Table 4 below is the addressing configuration of the device. Table 4. DDR Addressing Figure 17 is the functional block diagram of the DDR2 memory device. Page 42 of 83 BeagleBone System Reference Manual REF: BBONE_SRM RevA5.0.1 Figure 17. DDR Device Block Diagram 7.7.1 DDR 2 Design Figure 18 below is the schematic of the DDR implementation. The memory is placed as close to the processor as possible to minimize layout and signal issues. 3 3 3 3 3 3 3 3 3 3 3 3 3 3 J8 K8 K2 L8 K7 L7 K3 DDR_CLK DDR_CLKn DDR_CKE DDR_CSn DDR_RASn DDR_CASn DDR_WEn DDR_D[15..0] DDR_D0 DDR_D1 DDR_D2 DDR_D3 DDR_D4 DDR_D5 DDR_D6 DDR_D7 DDR_D8 DDR_D9 DDR_D10 DDR_D11 DDR_D12 DDR_D13 DDR_D14 DDR_D15 G8 G2 H7 H3 H1 H9 F1 F9 C8 C2 D7 D3 D1 D9 B1 B9 B7 A8 B3 E8 F7 F3 DDR_DQS1 DDR_DQSN1 DDR_DQM1 DDR_DQSN0 DDR_DQS0 DDR_DQM0 A1 E1 M9 R1 J9 VDDS_DDR E3 P9 J3 N1 A3 R7 R3 E2 A2 DDR_A[13..0] U6 CK CKn CKE CSn RASn CASn WEn DQ0 DQ1 DQ2 DQ3 DQ4 DQ5 DQ6 DQ7 DQ8 DQ9 DQ10 DQ11 DQ12 DQ13 DQ14 DQ15 UDQS UDQSn UDM LDQSn LDQS LDM VDD VDD VDD VDD VDD VSS VSS VSS VSS VSS RFU2 RFU1 NC1 NC2 A0 A1 A2 A3 A4 A5 A6 A7 A8 A9 A10 A11 A12 (RFU)A13 BA0 BA1 BA2 ODT VDDQ VDDQ VDDQ VDDQ VDDQ VDDQ VDDQ VDDQ VDDQ VDDQ VSSQ VSSQ VSSQ VSSQ VSSQ VSSQ VSSQ VSSQ VSSQ VSSQ VDDL VSSDL VREF M8 M3 M7 N2 N8 N3 N7 P2 P8 P3 M2 P7 R2 R8 L2 L3 L1 DDR_A0 DDR_A1 DDR_A2 DDR_A3 DDR_A4 DDR_A5 DDR_A6 DDR_A7 DDR_A8 DDR_A9 DDR_A10 DDR_A11 DDR_A12 DDR_A13R 0,1% DDR_BA0 DDR_BA1 DDR_BA2 DDR_A13 R120 DDR_BA[2..0] K9 DDR_ODT A9 C1 C3 C7 C9 E9 G1 G3 G7 G9 VDDS_DDR H8 B2 D2 F2 H2 A7 E7 B8 D8 F8 J1 VDDS_DDR J7 J2 DDR_VREF MT47H128M16RT-25E:C DDR2 SDRAM DGND C118 0.01uf ,16V DGND Figure 18. DDR Design Page 43 of 83 DGND 3 3 3 3 BeagleBone System Reference Manual REF: BBONE_SRM RevA5.0.1 The DDR2 connects direct to the processor and no external interface devices are required. Power is supplied to the DDR2 via the 1.8V rail on the TPS65217B. 7.7.2 DDR VTP Termination Resistor There is a requirement for a 50 ohm 1% termination resistor, R76, on the DDR interface. You will notice that the one used on the board design is a 50W wire wound resistor. The reason for this is cost. This resistor can be expensive and at the time of the design, this was the least expensive one package available. On the Rev A4 design, we added two more resistors, R217 and R218, to allow for a 0603 and 0805 package for applications where space is critical and to give us more options where parts availability is concerned. 7.7.3 User LEDs Four user LEDS are provided via GPIO pins on the processor. Figure 19 below shows the LED circuitry. 2 SY S_5V FB4 150OHM800mA 1 VDD_LED C100 D4 DGND DGND 3 6 4 R118 100K,1% Q2A 5 DMC56404 R119 100K,1% DGND DGND 598-8170-107F Q2B DMC56404 47k 1 598-8170-107F 10k 2 DMC56404 R117 100K,1% USR3 47k 3 3 3 DGND Q1B 10k 6 3 LEDCC 598-8170-107F 47k DGND DMC56404 47k R116 100K,1% 5 Q1A 10k USR0 10k 3 2 D5 USR2 GRN 598-8170-107F USR1 GRN GRN USR0 R99 470,5% LEDDC D3 GRN LEDAC R98 470,5% 1 D2 LEDBC DGND R97 470,5% 4 R96 470,5% 4.7uF,6.3V DGND DGND USR1 USR2 USR3 Figure 19. User LEDS Q1 and Q2 provide level shifting from the processor to drive the LEDs that are connected the SYS_5V rail. FB4 provides noise immunity to the system by the LEDS which can be a source of noise back into the system rail. Each LED is controlled by setting the appropriate GPIO bit HI. At power up all LEDs are off. Table 5 is the GPIO USER LED assignments. Page 44 of 83 BeagleBone System Reference Manual REF: BBONE_SRM Table 5. User LED Control LED User 0 User 1 User 2 User 3 7.8 RevA5.0.1 GPIO GPIO1_21 GPIO1_22 GPIO1_23 GPIO1_24 10/100 Ethernet The 10/100 Ethernet uses a SMSC LAN8710A Ethernet PHY and interfaces to the processor using the MII interface. This section covers that design. 7.8.1 Ethernet PHY Design Figure 20 below is the design of the 10/100 PHY section of the board. VDD_PHY A C119 0.1uf ,16V 2 FB5 DGND C122 0.1uf ,16V 100,1% 100,1% 100,1% 100,1% 100,1% 100,1% 100,1% R206 100,1% R207 R139 100,1% 100,1% RXD3/PHYAD2 RXD2/RMIISEL RXD1/MODE1 RXD0/MODE0 RXDV REFCLKO RXER/PHY AD0 TXCLK COL/CRS_DV/MODE2 CRS_DV/MODE2 R200 0,1%,DNI SY S_RESETn R140 PHY _XTAL1 1M,1%,DNI PHY _XTAL2 R199 0,1% 19 5 RCLKIN 4 R144 10,1% VDD_PHYA VDDCR TXP TXN TXP TXN 31 30 RXP RXN PHYX C131 LED1/REGOFF LED2/nINTSEL nINT/TXER/TXD4 RBIAS QFN32_5X5MM_EP3P3MM 3 2 DGND DGND C132 30pF,50V C128 C129 32 DGND DGND Page 45 of 83 DGND DGND GRNA Y ELA 18 RBIAS R145 12.1K,1% 1 25.000MHz XTAL2_5X3P2_SMD 30pF,50V C127 15pF,DNI15pF,DNI15pF,DNI 15pF,DNI DGND Y4 2 49.9,1% R130 29 28 C126 nRST XTAL2 DGND RXP RXN U15 TXCLK TXEN LAN8710A TXD0 TXD1 TXD2 TXD3 COL/CRS_DV/MODE2 CRS XTAL1/CLKIN C125 1uF,10V 49.9,1% R129 6 1 27 VDD2A VDD1A 12 20 21 22 23 24 25 15 14 MDIO MDC RXD3/PHY AD2 RXD2/RMIISEL RXD1/MODE1 RXD0/MODE0 RXDV RXCLK/PHYAD1 RXER/RXD4/PHYAD0 33 11,3 16 17 8 9 10 11 26 7 13 VDDIO DGND GND_EP RMII1_TXCLK RMII1_TXEN RMII1_TXD0 RMII1_TXD1 RMII1_TXD2 RMII1_TXD3 RMII1_COL RMII1_CRS_DV R205 R153 R132 R135 R208 R136 R137 DGND C124 470pF 50V 5% C123 0.1uf ,16V R131 4 4 4 4 4 4 4 4 MDIO_DATA MDIO_CLK RMII1_RXD3 RMII1_RXD2 RMII1_RXD1 RMII1_RXD0 RMII1_RXDV RMII1_RXCLK RMII1_RXERR 10,1%,DNI 1.5K,5% 4 4 4 4 4 4 4 4 4 R209 RMII1_REFCLK DGND C121 4.7uF,6.3V PHY_VDDCR DGND 4 C120 0.1uf ,16V 49.9,1% R134 1 150OHM800mA 49.9,1% R133 VDD_3V3B DGND BeagleBone System Reference Manual REF: BBONE_SRM RevA5.0.1 P11 5 3 6 1 2 4 TXP TXN RXP RXN Y ELA GRNA R218 470,5% Y EL_C R219 470,5% GRN_C 11 12 10 9 TCT TD+ TDRD+ RDRCT 7 NC 8 GND 13 14 Y ELC SHD1 Y ELA SHD2 GRNC GRNA DGND WE_7499010211A DGND R217 TCT_RCT C167 VDD_PHY A R202 0,1% ESD_RING .1,0805 DGND 0.022uF,10V DGND Figure 20. 10/100 Ethernet PHY Design 7.8.2 Processor Signal Description The Table 6 describes the signals between the processor and the LAN8710A. The BALL column is the pin number on the processor. The SIGNAL name is the generic name of the signal on the processor. The PHY column is the pin number of the PHY. Page 46 of 83 REF: BBONE_SRM Table 6. 7.8.3 BeagleBone System Reference Manual RevA5.0.1 Processor Ethernet Signals Clocking Mode The LAN8710A provides the clock to the processor and is generated by the onboard 25MHz crystal Y4. There are independent clocks for the transmit channel (MII Transmit Clock) and for the receive channel (MII Receive clock). 7.8.4 PHY Mode The PHY operates in the 10/100 mode with auto negotiation enabled. This is set via the resistors as described in Figure 21 which are sampled by the PHY when coming out of reset. It is possible for SW to override this setting if required by setting these bits via the MDIO channel. Page 47 of 83 BeagleBone System Reference Manual REF: BBONE_SRM RevA5.0.1 VDD_3V3B 10K,1%,DNI R215 R213 10K,1%,DNI R124 10K,1% R123 10K,1%R122 10K,1%,DNI R211 RXD1/MODE1 M ODE0 RMISEL PHYAD1 PHYAD0 10K,1% RXD0/MODE0 10K,1%,DNI R126 PHYAD0 M ODE2 M ODE1 CRS_DV/MODE2 RXER/PHY AD0 RXD2/RMIISEL RXD3/PHYAD2 R212 R214 R216 10K,1% 10K,1% 10K,1% 10K,1%,DNI R198 R5 10K,1%,DNI R127 10K,1%,DNI 10K,1% R125 nINT/RXCLK/PHY AD1 DGND Figure 21. 10/100 Ethernet PHY Default Settings By adding pull up or pull down resistors, the default mode of the PHY can be set via HW. Seven pairs of resistors are provided on the board to set the mode. Pins MODE0-1 set the operating mode of the PHY. Default mode is 111 as set by the populating of R122-124. This enables all operating modes and auto negotiation. PHYAD0-2 sets the default address of the PHY. Populating R124-R126 set the default of 0. It is not expected to be set to anything other than this, but the other option was enabled just in case. RMIISEL sets the mode to RMII if R211 is installed. MII is the default mode used in this design, so R212 needs to be installed and R211 is not to be installed. 7.8.5 MDIO Interface The MDIO interface is the control channel interface between the processor and the LAN8710A. Via this interface all of the internal PHY registers can be read and set by the processor and important status information can be read. Page 48 of 83 REF: BBONE_SRM 7.8.6 BeagleBone System Reference Manual RevA5.0.1 PHY Reset The PHY reset signal is connected to the main board reset and is reset on power up. 7.8.7 Status LEDs They Ethernet connector has a Yellow and Green LED. The Green LED will be on when a link is established. It flashes off when data is transferred. The Yellow status LED will work differently for revision A3 and A4. A3...The Yellow LED is OFF when the link is 100M and ON when it is 10M. A4...The Yellow LED is ON when the link is 100M and OFF when it is 10M. However, after removing R219 which is required, operation reverts back to the same as A3. A5… Yellow LED is OFF when the link is 100M and ON when it is 10M. 7.8.8 Power The PHY is powered via the 3.3VB rail from the TPS65217B. A filter is provided between the 3.3VB rail and the PHY. The internal LDO is used to power the internal rails. 7.9 USB Host A single USB Host port is provided on the board. It is driven by USB port 1 of the processor. The port can deliver up to 500mA of current provided that much current is available from the power supply. In the scenario where the board is totally powered from the USB input, the power supplied will be much less and dependent on how much current is available after driving the board and any daughter cards that may be attached. 7.9.1 USB Host design The board has a single USB host connector accessible via P2 a type A female connector. Figure 22 below is the USB Host design. Page 49 of 83 BeagleBone System Reference Manual REF: BBONE_SRM RevA5.0.1 P2 USB-A Conn. - 87520-xx1xx 4 4 4 1 VBUS 2 D3 D+ 4 GND USB1_DM USB1_DP USB1_ID SHIELD SHIELD 5 6 SY S_5V DGND U9 2 3 4 1 4 USB1_DRVVBUS + R147 C133 10K,1%100uF,6.3V DGND DGND IN OUT IN OUT EN OUT GND OC PAD 8 7 6 5 9 USB1_VBUS VDD_3V3B R146 0,1% 1 U10 D+ 2 TPS2051 (DGN) R148 10K,1% DGND VBUS DNC 3 ID DGND GND 4 6 C134 0.01uf ,16V 5 4 TPD4S012 DGND USB1_OC 3 DGND Figure 22. USB Host Design The USB port on the processor is an OTG port. In order to force the host function needed, the ID pin, USB_ID, is grounded permanently by R146. U9, a TPS2051, is the power switch that controls the 5VDC to the USB port. It is turned on by the processor via USB1_DRVVBUS signal. The USB1_VBUS signal is a confirmation back to the processor that the switch is activated and that 5V is connected to the USB Host connector. In the event of an over current condition, the switch will signal the processor of the event, via USB1_OC, and the switch will shut down. R148 is a pullup to provide the HI voltage level because the OC signal on U9 is an open drain pin. C133 provides extra current when devices are inserted into the connector per the USB specification. The amount of current the switch can provide is limited by the available current from the main power source. In order to handle high current devices, you need to power the board from the DC input connector and not USB. Powering from USB can in, most cases, supply enough current to run a thumbdrive or low current device. U10 is an ESD protection device intended to protect the processor. 7.10 SD Connector The board is populated with a microSD small form factor SD slot. It will support High capacity cards. The voltage rail for the connector is 3.3VA. A card detector output is provided from the connector to the CD/EMU4 signal. Figure 23 shows the connections to the microSD connector. Page 50 of 83 BeagleBone System Reference Manual REF: BBONE_SRM RevA5.0.1 3 3 3 3 3 3 R194 R193 R192 R191 R195 10K,1% 10K,1% 10K,1% 10K,1% 10K,1% 10K,1% R190 VDD_3V3 MMC0_DAT2 MMC0_DAT3 MMC0_CMD MMC0_CLKO MMC0_DAT0 MMC0_DAT1 C159 10uF,10V C160 0.1uf ,16V DGND 1 2 3 4 5 6 7 8 P4 DAT2 GND CD/DAT3 CD CMD GND3 VDD GND4 CLOCK GND5 VSS GND6 DAT0 GND7 microSD DAT1 GND8 9 10 11 12 13 14 15 16 DGND SD_CD R196 10K,1% VDD_3V3 R197 0,1% SCHA5B0200 DGND 10,4 uSD Connector CD/EMU4 Figure 23. SD Connector Design There are pullup resistors on all the signals to provide additional drive strength and to increase the rise time of the signals. The SD_CD is the signal that indicates to the processor that the card is inserted. The signal is a contact point on the connector and R196 provides the logic hi signal that is grounded whenever there is no card inserted. When the card is inserted, the signal will go high. R197 is provided as an option to allow this signal to be removed from the processor for use as the EMU4 signal by the optional JTAG connector. The connector is located on the bottom side of the board and the card should be inserted with the label side up and the contact pins down. This connector is a Push-Push connector. To insert the card push the card in until it clicks and then release. To remove the card, push the card in and the connector will release the card and eject the card. WARNING: DO NOT PULL THE CARD OUT TO REMOVE IT OR YOU MAY DAMAGE THE CONNECTOR. 7.11 EEPROM The BeagleBone is equipped with a single CAT24C256W EEPROM to allow the SW to identify the board. Table 7 below defined the contents of the EERPOM. Page 51 of 83 BeagleBone System Reference Manual REF: BBONE_SRM Table 7. RevA5.0.1 EEPROM Contents Name Size (bytes) Contents Header 4 0xAA, 0x55, 0x33, EE Board Name 8 Name for board in ASCII: A335BONE Version 4 Hardware version code for board in ASCII: 00A3 Serial Number 12 Serial number of the board. This is a 12 character string which is: WWYY4P16nnnn where: WW = 2 digit week of the year of production YY = 2 digit year of production nnnn = incrementing board number Configuration Option 32 Codes to show the configuration setup on this board. 0000000000000000000000000000000 RSVD 6 000000 RSVD 6 000000 RSVD 6 000000 Available 32702 Available space for other non-volatile codes/data Figure 24 is the design of the EEPROM circuit. VDD_3V3B 2,4 2,4 6 5 I2C0_SCL I2C0_SDA 1 2 3 U7 SCL SDA VCC VSS A0 A1 A2 WP 8 7 CAT24C256W DGND C102 0.1uf ,16V 4 WP R210 10K,1%,DNIDGND 32KX8 (256Kb) Figure 24. EEPROM Design The EEPROM is accessed by the processor using the I2C 0 bus. The EEPROM is not write protected. R21 if installed would invoke the write protection. The WP pin has an internal pulldown on it so that if removed the pin is grounded. The first 48 locations should not be written to if you choose to use the extras storage space in the EEPROM. If you do, it could prevent the board from booting properly as the SW uses this information to determine how to set up the board. 7.12 ADC Interface The processor has 8 ADC (Analog to Digital) converter inputs. The signals are 1.8V only interfaces. One of these, AD7, is connected to the TPS65217B and used for measuring voltages and current via the TPS65217B. Page 52 of 83 REF: BBONE_SRM BeagleBone System Reference Manual RevA5.0.1 7.12.1 ADC Inputs The primary purpose of the ADC pins was intended for use as a Touchscreen controller but can be used as a general purpose ADC. Each signal is a 12b successive approximation register (SAR) ADC. Sample rate is 00K samples per second. There is only one ADC in the processor and it can be connected to any of the 8 ADC pins. 7.12.2 VDD_ADC Interface The signal VDD_ADC is provided via the expansion header, but is not a voltage rail that is to be used to power anything on an expansion board. It is supplied from the 1.8V rail of the TPS65217B and is run through an inductor for noise isolation. It is there if need for external circuitry to have access to the VREF rail of the ADC or to add additional filtering via a capacitor if needed. Page 53 of 83 REF: BBONE_SRM 7.13 BeagleBone System Reference Manual RevA5.0.1 Expansion Headers The expansion interface on the board is comprised of two 46 pin connectors. All signals on the expansion headers are 3.3V unless otherwise indicated. NOTE: Do not connect 5V logic level signals to these pins or the board will be damaged. 7.13.1 Expansion Header P8 Table 8 shows the default pinout of the P8 expansion header. Other signals can be connected to this connector based on setting the pin mux on the processor, but this is the default settings on power up. The SW is responsible for setting the default function of each pin. Table 8. SIGNAL NAME Expansion Header P8 Pinout PROC CONN PROC SIGNAL NAME GND 1 2 GND GPIO1_6 R9 3 4 T9 GPIO1_7 GPIO1_2 R8 5 6 T8 GPIO1_3 TIMER4 R7 7 8 T7 TIMER7 TIMER5 T6 9 10 U6 TIMER6 GPIO1_13 R12 11 12 T12 GPIO1_12 EHRPWM2B T10 13 14 T11 GPIO0_26 GPIO1_15 U13 15 16 V13 GPIO1_14 GPIO0_27 EHRPWM2A U12 17 18 V12 GPIO2_1 U10 19 20 V9 GPIO1_31 GPIO1_30 U9 21 22 V8 GPIO1_5 GPIO1_4 U8 23 24 V7 GPIO1_1 GPIO1_0 U7 25 26 V6 GPIO1_29 GPIO2_22 U5 27 28 V5 GPIO2_24 GPIO2_23 R5 29 30 R6 GPIO2_25 UART5_CTSN V4 31 32 T5 UART5_RTSN UART4_RTSN V3 33 34 U4 UART3_RTSN UART4_CTSN V2 35 36 U3 UART3_CTSN UART5_TXD U1 37 38 U2 UART5_RXD GPIO2_12 T3 39 40 T4 GPIO2_13 GPIO2_10 T1 41 42 T2 GPIO2_11 GPIO2_8 R3 43 44 R4 GPIO2_9 GPIO2_6 R1 45 46 R2 GPIO2_7 Page 54 of 83 BeagleBone System Reference Manual REF: BBONE_SRM RevA5.0.1 7.13.2 P8 Signal Pin Mux Options Table 9 shows the other signals that can be connected to each pin of P8 based on the settings of the registers in the processor for modes 0-3. Table 9. PIN PROC NAME P8 Mux Options Modes 0-3 MODE0 MODE1 MODE2 MODE3 GND 1 2 3 4 5 R9 T9 R8 GND GPIO1_6 GPIO1_7 GPIO1_2 gpmc_ad6 gpmc_ad7 gpmc_ad2 mmc1_dat6 mmc1_dat7 mmc1_dat2 6 T8 GPIO1_3 gpmc_ad3 mmc1_dat6 7 R7 TIMER4 gpmc_advn_ale timer4 8 T7 TIMER7 gpmc_oen_ren timer7 9 T6 TIMER5 gpmc_be0n_cle timer5 10 U6 TIMER6 gpmc_wen 11 R12 GPIO1_13 gpmc_ad13 lcd_data18 mmc1_dat5 timer6 mmc2_dat1 12 T12 GPIO1_12 GPMC_AD12 LCD_DATA19 MMC1_DAT4 MMC2_DAT0 13 T10 EHRPWM2B gpmc_ad9 lcd_data22 mmc1_dat1 mmc2_dat5 14 T11 GPIO0_26 gpmc_ad10 lcd_data21 mmc1_dat2 mmc2_dat6 15 U13 GPIO1_15 gpmc_ad15 lcd_data16 mmc1_dat7 mmc2_dat3 16 V13 GPIO1_14 gpmc_ad14 lcd_data17 mmc1_dat6 mmc2_dat2 17 U12 GPIO0_27 gpmc_ad11 lcd_data20 mmc1_dat3 mmc2_dat7 18 V12 lcd_memory_clk gpmc_wait1 mmc2_clk U10 GPIO2_1 EHRPWM2A gpmc_clk_mux0 19 gpmc_ad8 lcd_data23 mmc1_dat0 mmc2_dat4 20 V9 GPIO1_31 gpmc_csn2 gpmc_be1n mmc1_cmd 21 U9 GPIO1_30 gpmc_csn1 gpmc_clk mmc1_clk 22 V8 GPIO1_5 gpmc_ad5 23 U8 GPIO1_4 gpmc_ad4 mmc1_dat3 24 V7 GPIO1_1 gpmc_ad1 mmc1_dat1 25 U7 GPIO1_0 gpmc_ad0 mmc1_dat0 26 V6 GPIO1_29 gpmc_csn0 27 U5 GPIO2_22 lcd_vsync gpmc_a8 28 V5 GPIO2_24 lcd_pclk gpmc_a10 29 R5 GPIO2_23 lcd_hsync gpmc_a9 30 R6 GPIO2_25 lcd_ac_bias_en gpmc_a11 31 V4 UART5_CTSN lcd_data14 gpmc_a18 eQEP1_index mcasp0_axr1 32 T5 UART5_RTSN lcd_data15 gpmc_a19 eQEP1_strobe mcasp0_ahclkx 33 V3 UART4_RTSN lcd_data13 gpmc_a17 eQEP1B_in mcasp0_fsr 34 U4 UART3_RTSN lcd_data11 gpmc_a15 ehrpwm1B mcasp0_ahclkr 35 V2 UART4_CTSN lcd_data12 gpmc_a16 eQEP1A_in mcasp0_aclkr mmc1_dat5 Page 55 of 83 REF: BBONE_SRM BeagleBone System Reference Manual RevA5.0.1 PIN PROC NAME MODE0 MODE1 MODE2 MODE3 36 U3 UART3_CTSN lcd_data10 gpmc_a14 ehrpwm1A mcasp0_axr0 37 U1 UART5_TXD lcd_data8 gpmc_a12 ehrpwm1_tripzone_in mcasp0_aclkx 38 U2 UART5_RXD lcd_data9 gpmc_a13 ehrpwm0_synco 39 T3 GPIO2_12 lcd_data6 gpmc_a6 eQEP2_index 40 T4 GPIO2_13 lcd_data7 gpmc_a7 eQEP2_strobe 41 T1 GPIO2_10 lcd_data4 gpmc_a4 eQEP2A_in 42 T2 GPIO2_11 lcd_data5 gpmc_a5 eQEP2B_in 43 R3 GPIO2_8 lcd_data2 gpmc_a2 ehrpwm2_tripzone_in 44 R4 GPIO2_9 lcd_data3 gpmc_a3 ehrpwm0_synco 45 R1 GPIO2_6 lcd_data0 gpmc_a0 ehrpwm2A 46 R2 GPIO2_7 lcd_data1 gpmc_a1 ehrpwm2B mcasp0_fsx There are some signals that have not been listed here. Refer to the processor documentation for more information on these pins and detailed descriptions of all of the pins listed. In some cases there may not be enough signals to complete a group of signals that may be required to implement a total interface. The PROC column is the pin number on the processor. The PIN column is the pin number on the expansion header. The MODE columns are the mode setting for each pin. Setting each mode to align with the mode column will give that function on that pin. Page 56 of 83 BeagleBone System Reference Manual REF: BBONE_SRM RevA5.0.1 Table 10 shows the other P8 signals for modes 4-7. Table 10. PIN 1 PROC NAME GND 2 GND P8 Mux Options Modes 4-7 MODE4 MODE5 MODE6 MODE7 3 R9 GPIO1_6 gpio1[6] 4 T9 GPIO1_7 gpio1[7] 5 R8 GPIO1_2 gpio1[2] 6 T8 GPIO1_3 gpio1[3] 7 R7 TIMER4 gpio2[2] 8 T7 TIMER7 gpio2[3] 9 T6 TIMER5 gpio2[5] 10 U6 TIMER6 gpio2[4] 11 R12 GPIO1_13 eQEP2B_in gpio1[13] 12 T12 GPIO1_12 EQEP2A_IN gpio1[12] 13 T10 EHRPWM2B ehrpwm2B gpio0[23] 14 T11 GPIO0_26 ehrpwm2_tripzone_in gpio0[26] 15 U13 GPIO1_15 eQEP2_strobe gpio1[15] 16 V13 GPIO1_14 eQEP2_index gpio1[14] 17 U12 GPIO0_27 ehrpwm0_synco gpio0[27] 18 V12 19 U10 GPIO2_1 EHRPWM2A 20 V9 GPIO1_31 gpio1[31] 21 U9 GPIO1_30 gpio1[30] 22 V8 GPIO1_5 gpio1[5] 23 U8 GPIO1_4 gpio1[4] 24 V7 GPIO1_1 gpio1[1] 25 U7 GPIO1_0 gpio1[0] 26 V6 GPIO1_29 gpio1[29] 27 U5 GPIO2_22 gpio2[22] 28 V5 GPIO2_24 gpio2[24] 29 R5 GPIO2_23 gpio2[23] 30 R6 GPIO2_25 gpio2[25] 31 V4 UART5_CTSN uart5_rxd uart5_ctsn gpio0[10] 32 T5 UART5_RTSN mcasp0_axr3 uart5_rtsn gpio0[11] 33 V3 UART4_RTSN mcasp0_axr3 uart4_rtsn gpio0[9] 34 U4 UART3_RTSN mcasp0_axr2 uart3_rtsn gpio2[17] 35 V2 UART4_CTSN mcasp0_axr2 uart4_ctsn gpio0[8] 36 U3 UART3_CTSN uart3_ctsn gpio2[16] 37 U1 UART5_TXD uart2_ctsn gpio2[14] mcasp0_fsr ehrpwm2A uart5_txd Page 57 of 83 gpio2[1] gpio0[22] REF: BBONE_SRM BeagleBone System Reference Manual MODE5 RevA5.0.1 PIN PROC NAME MODE4 MODE6 MODE7 38 U2 UART5_RXD uart5_rxd uart2_rtsn gpio2[15] 39 T3 GPIO2_12 40 T4 GPIO2_13 41 T1 GPIO2_10 gpio2[10] 42 T2 GPIO2_11 gpio2[11] 43 R3 GPIO2_8 gpio2[8] 44 R4 GPIO2_9 gpio2[9] 45 R1 GPIO2_6 gpio2[6] 46 R2 GPIO2_7 gpio2[7] gpio2[12] pr1_edio_data_out7 gpio2[13] There are some signals that have not been listed here. Refer to the processor documentation for more information on these pins and detailed descriptions of all of the pins listed. In some cases there may not be enough signals to complete a group of signals that may be required to implement a total interface. The PROC column is the pin number on the processor. The PIN column is the pin number on the expansion header. The MODE columns are the mode setting for each pin. Setting each mode to align with the mode column will give that function on that pin. Page 58 of 83 BeagleBone System Reference Manual REF: BBONE_SRM RevA5.0.1 7.13.3 Expansion Header P9 Table 11 lists the signals on connector P9. Other signals can be connected to this connector based on setting the pin mux on the processor, but this is the default settings on power up. Signals highlighted in yellow are changes from the previous revision of the SRM. Table 11. SIGNAL NAME Expansion Header P9 Pinout PIN CONN PIN GND 1 2 GND VDD_3V3EXP 3 4 VDD_3V3EXP VDD_5V 5 6 VDD_5V SYS_5V 7 8 SYS_5V PWR_BUT* UART4_RXD T17 UART4_TXD U17 GPIO1_16 R13 I2C1_SCL A16 I2C2_SCL D17 UART2_TXD B17 GPIO1_17 V14 GPIO3_21 A14 GPIO3_19 C13 SPI1_D0 B13 SPI1_SCLK A13 AIN4 C8 AIN6 A5 AIN2 B7 AIN0 B6 CLKOUT2 D14 GND GND 9 11 13 15 17 19 21 23 25 27 29 31 33 35 37 39 41 10 A10 12 U18 14 U14 16 T14 18 B16 20 D18 22 A17 24 D15 26 D16 28 C12 30 D12 32 VDD_ADC(1.8V) GNDA_ADC 34 36 A5 38 A7 40 C7 C18 42 43 44 GND 45 46 GND SIGNAL NAME SYS_RESETn GPIO1_28 EHRPWM1A EHRPWM1B I2C1_SDA I2C2_SDA UART2_RXD UART1_TXD UART1_RXD SPI1_CS0 SPI1_D1 AIN5 AIN3 AIN1 GPIO0_7 *PWR_BUT is a 5V level as pulled up internally by the TPS65217B. It is activated by pulling the signal to GND. Page 59 of 83 BeagleBone System Reference Manual REF: BBONE_SRM 7.13.3.1 RevA5.0.1 Connector P9 Signal Pin Mux Options Table 12 gives the pin mux options for the signals for connector P9 for modes 0-3. Table 12. PIN PROC SIGNAL NAME 1 GND 2 GND 3 DC_3.3V 4 DC_3.3V 5 VDD_5V 6 VDD_5V 7 SYS_5V 8 SYS_5V 9 PWR_BUT P9 Mux Options Modes 0-3 MODE0 MODE1 MODE2 MODE3 10 A10 SYS_RESETn RESET_OUT 11 T17 UART4_RXD gpmc_wait0 mii2_crs gpmc_csn4 rmii2_crs_dv 12 U18 GPIO1_28 gpmc_be1n mii2_col gpmc_csn6 mmc2_dat3 13 U17 UART4_TXD gpmc_wpn mii2_rxerr gpmc_csn5 rmii2_rxerr 14 U14 EHRPWM1A gpmc_a2 mii2_txd3 rgmii2_td3 mmc2_dat1 15 R13 GPIO1_16 gpmc_a0 gmii2_txen rmii2_tctl mii2_txen 16 T14 EHRPWM1B gpmc_a3 mii2_txd2 rgmii2_td2 mmc2_dat2 17 A16 I2C1_SCL spi0_cs0 mmc2_sdwp I2C1_SCL ehrpwm0_synci 18 B16 I2C1_SDA spi0_d1 mmc1_sdwp I2C1_SDA ehrpwm0_tripzone 19 D17 I2C2_SCL uart1_rtsn timer5 dcan0_rx I2C2_SCL 20 D18 I2C2_SDA uart1_ctsn timer6 dcan0_tx I2C2_SDA 21 B17 UART2_TXD spi0_d0 uart2_txd I2C2_SCL ehrpwm0B 22 A17 UART2_RXD spi0_sclk uart2_rxd I2C2_SDA ehrpwm0A 23 V14 GPIO1_17 gpmc_a1 gmii2_rxdv rgmii2_rxdv mmc2_dat0 24 D15 UART1_TXD uart1_txd mmc2_sdwp dcan1_rx I2C1_SCL 25 A14 GPIO3_21 mcasp0_ahclkx eQEP0_strobe mcasp0_axr3 mcasp1_axr1 26 D16 UART1_RXD uart1_rxd mmc1_sdwp dcan1_tx I2C1_SDA 27 C13 GPIO3_19 mcasp0_fsr eQEP0B_in mcasp0_axr3 mcasp1_fsx 28 C12 SPI1_CS0 mcasp0_ahclkr ehrpwm0_synci mcasp0_axr2 spi1_cs0 29 B13 SPI1_D0 mcasp0_fsx ehrpwm0B 30 D12 SPI1_D1 mcasp0_axr0 ehrpwm0_tripzone spi1_d1 31 A13 SPI1_SCLK mcasp0_aclkx ehrpwm0A spi1_sclk 32 33 VADC C8 AIN4 AGND A8 AIN6 34 35 Page 60 of 83 spi1_d0 REF: BBONE_SRM BeagleBone System Reference Manual PIN PROC SIGNAL NAME 36 B8 AIN5 37 B7 AIN2 38 A7 AIN3 39 B6 AIN0 40 C7 AIN1 41 D14 CLKOUT2 xdma_event_intr1 GPIO0_7 eCAP0_in_PWM0_ out 42 C18 43 GND 44 GND 45 GND 46 GND MODE0 MODE1 uart3_txd MODE2 RevA5.0.1 MODE3 tclkin clkout2 spi1_cs1 pr1_ecap0_ecap_cap in_apwm_o There are some signals that have not been listed here. Refer to the processor documentation for more information on these pins and detailed descriptions of all of the pins listed. In some cases there may not be enough signals to complete a group of signals that may be required to implement a total interface. The PROC column is the pin number on the processor. The PIN column is the pin number on the expansion header. The MODE columns are the mode setting for each pin. Setting each mode to align with the mode column will give that function on that pin. Page 61 of 83 BeagleBone System Reference Manual REF: BBONE_SRM RevA5.0.1 Table 13 gives the pin mux options for the signals for connector P9 for modes 4-7. Table 13. PIN PROC 1 SIGNAL NAME GND 2 GND 3 DC_3.3V 4 DC_3.3V 5 VDD_5V 6 VDD_5V 7 SYS_5V 8 SYS_5V 9 P9 Mux Options Modes 4-7 MODE4 MODE5 MODE6 MODE7 PWR_BUT 10 A10 SYS_RESETn 11 T17 UART4_RXD mmc1_sdcd uart4_rxd_mux2 gpio0[30] 12 U18 GPIO1_28 gpmc_dir mcasp0_aclkr_mux3 gpio1[28] 13 U17 UART4_TXD mmc2_sdcd uart4_txd_mux2 gpio0[31] 14 U14 EHRPWM1A gpmc_a18 ehrpwm1A_mux1 gpio1[18] 15 R13 GPIO1_16 gpmc_a16 ehrpwm1_tripzone_input gpio1[16] 16 T14 EHRPWM1B gpmc_a19 ehrpwm1B_mux1 gpio1[19] 17 A16 I2C1_SCL gpio0[5] 18 B16 I2C1_SDA gpio0[4] 19 D17 I2C2_SCL spi1_cs1 gpio0[13] 20 D18 I2C2_SDA spi1_cs0 gpio0[12] 21 B17 UART2_TXD EMU3_mux1 gpio0[3] 22 A17 UART2_RXD EMU2_mux1 gpio0[2] 23 V14 GPIO1_17 ehrpwm0_synco gpio1[17] 24 D15 UART1_TXD gpmc_a17 gpio0[15] 25 A14 GPIO3_21 26 D16 UART1_RXD 27 C13 GPIO3_19 EMU2_mux2 gpio3[19] 28 C12 SPI1_CS0 eCAP2_in_PWM2_out gpio3[17] 29 B13 SPI1_D0 mmc1_sdcd_mux1 gpio3[15] 30 D12 SPI1_D1 mmc2_sdcd_mux1 gpio3[16] 31 A13 SPI1_SCLK mmc0_sdcd_mux1 gpio3[14] 32 33 C8 AIN4 GNDA_ADC A5 AIN6 gpio3[21] gpio0[14] VDD_ADC (1.8V_ 34 35 EMU4_mux2 Page 62 of 83 REF: BBONE_SRM BeagleBone System Reference Manual PIN PROC SIGNAL NAME 36 A5 AIN5 37 B7 AIN2 38 A7 AIN3 39 B6 AIN0 40 C7 AIN1 41 D14 CLKOUT2 timer7_mux1 42 C18 GPIO0_7 spi1_sclk 43 GND 44 GND 45 GND 46 GND MODE4 MODE5 mmc0_sdwp MODE6 MODE7 EMU3_mux0 gpio0[20] xdma_event_intr2 gpio0_7 RevA5.0.1 There are some signals that have not been listed here. Refer to the processor documentation for more information on these pins and detailed descriptions of all of the pins listed. In some cases there may not be enough signals to complete a group of signals that may be required to implement a total interface. The PROC column is the pin number on the processor. The PIN column is the pin number on the expansion header. The MODE columns are the mode setting for each pin. Setting each mode to align with the mode column will give that function on that pin. Page 63 of 83 BeagleBone System Reference Manual REF: BBONE_SRM RevA5.0.1 7.13.4 PMIC Expansion Header There is an additional connector that brings out some additional signals from the TPS65217B power management chip. Figure 25 shows the PMIC expansion connector. P6 BAT BAT_TEMP BL_ISET1 BL_IN BL_SINK2 2 4 6 8 10 1 3 5 7 9 BAT BAT_SENSE BL_ISET2 BL_OUT BL_SINK1 HDR5x2 Figure 25. PMIC Expansion Header 7.13.5 Backlight Interface The most useful interface provided is the backlight interface which is very useful for powering the backlight of LCD panels. The Backlight circuit is a boost converter and two current sinks capable of driving up to 2x10 LEDs at 25mA or a single string at 50mA of current. Two current levels can be programmed using two external resistors and brightness dimming is supported by an internal PWM signal under I2C control. Both current sources are controlled together and cannot operate independently. The boost output voltage is internally limited to 39V. LED current is selected through the ISEL bit of the same register as is the PWM frequency. By default, the PWM frequency is set to 200Hz but can be changed to 100Hz, 500Hz, and 1000Hz. The PWM duty cycle can be adjusted from 1% to 100% in 1% steps through the WLEDCTRL2 register. If only a single WLED string is required, short both ISINK pins together and connect them to the Cathode of the diode string. Note that the LED current in this case is doubled and to compensate, the RSET resistors must be doubled as well. Figure 26 below shows the two different circuits. Figure 26. Backlight Circuitry For more information on working with this interface, refer to the TPS65217B datasheet. Page 64 of 83 REF: BBONE_SRM BeagleBone System Reference Manual RevA5.0.1 7.13.6 Battery Interface There is also a battery charger interface. This interface can be used by anyone wanting to experiment with batteries and battery charging. However, as a source for powering the BeagleBone, this interface is not practical. The reason for this is that the maximum battery voltage is 3.7V. The LDOs on the TPS65217B drop out at 200mv, meaning that the 3.3V LDOS cannot supply the needed 3.3V after the battery starts discharging. The best you can do is to work down to a battery level of 3.5V. You would need a boost converter to take the VDD_SYS rail to at least a constant 3.5V to keep the LDOs active. Figure 27 shows the battery circuitry inside the TPS65217B. Figure 27. Battery Circuitry Page 65 of 83 BeagleBone System Reference Manual REF: BBONE_SRM 8.0 RevA5.0.1 Cape Board Support The BeagleBone has the ability to accept up to four expansion boards or Capes that can be stacked onto the expansion headers. The word Cape comes from the shape of the board as it is fitted around the Ethernet connector on the main board. This notch acts as a key to insure proper orientation of the expansion board. This section describes the rules for creating Capes to insure proper operation with the BeagleBone and proper interoperability with other Capes that are intended to co-exist on with the Cape. Over time, this specification will change and be updated, so please refer to the latest version of this manual prior to designing your own expansion cards to get the latest information. 8.1 EEPROM Each Cape must have its own EEPROM containing information that will allow the SW to identify the board and to configure the expansion headers pins as needed. The one exception is proto boards intended for prototyping. They may or may not have an EEPROM on them. EEPROMs are required for all Capes sold in order for them operate correctly when plugged into the Beagle Bone. The address of the EEPROM will be set via either jumpers or a dipswitch on each expansion board. Figure 28 below is the design of the EEPROM circuit. R142 R138 R128 4.75K 4.75K 4.75K U18 SCL SDA SW1 SW1_A0 SW1_A1 SW1_A3 SW DIP-2 1 2 3 A0 A1 A2 VCC VSS WP 8 4 C130 0.1uF 7 CAT24C256W DGND Figure 28. Expansion Board EEPROM Page 66 of 83 2 I2C2_SCL I2C2_SDA VDD_3V3 6 5 1 2,4,6 2,4,6 5.6K,5% 5.6K,5% R220 R221 VDD_3V3 DGND REF: BBONE_SRM BeagleBone System Reference Manual RevA5.0.1 The EEPROM used is the same one as is used on the BeagleBone, a CAT24C256. The CAT24C256 is a 256 kb Serial CMOS EEPROM, internally organized as 32,768 words of 8 bits each. It features a 64−byte page write buffer and supports the Standard (100 kHz), Fast (400 kHz) and Fast−Plus (1 MHz) I2C protocol. The addressing of this device requires two bytes for the address which is not used on smaller size EEPROMs, which only require one byte. Other compatible devices may be used as well. Make sure the device you select supports 16 bit addressing. The package used is at the discretion of the Cape designer. 8.1.1 EEPROM Address In order for each Cape to have a unique address, a board ID scheme is used that sets the address to be different depending on the order in which it is stacked onto the main board. A two position dipswitch or jumpers is used to set the address pins of the EEPROM. It is the responsibility of the user to set the proper address for each board. Address line A2 is always tied high. This sets the allowable address range for the expansion cards to 0x54 to 0x57. All other I2C addresses can be used by the user in the design of their Capes. But, these addresses must not be used other than for the board EEPROM information. 8.1.2 I2C Bus The EEPROMs on each expansion board is connected to I2C2 on connector P9 pins 19 and 20. For this reason I2C2 must always be left connected and should not be changed by SW to remove it from the expansion header pin mux settings. If this is done, then the system will be unable to detect the Capes. The I2C signals require pullup resistors. Each board must have a 5.6K resistor on these signals. With four Capes installed this will be an affective resistance of 1.4K if all Capes were installed. As more Capes are added the resistance is increased to overcome capacitance added to the signals. When no Capes are installed the internal pullup resistors must be activated inside the processor to prevent I2C timeouts on the I2C bus. Page 67 of 83 BeagleBone System Reference Manual REF: BBONE_SRM 8.1.3 RevA5.0.1 EEPROM Data Format Table 14 below shows the format of the contents of the expansion board EEPROM. Table 14. Name Offset Expansion Board EEPROM Size (bytes) Contents Header 0 4 0xAA, 0x55, 0x33, 0xEE EEPROM Format Revision 4 2 Revision number of the overall format of this EEPROM in ASCII =A0 Board Name 6 32 Name of board in ASCII Version 38 4 Hardware version code for board in ASCII Manufacturer 42 16 ASCII name of the manufacturer Part Number 60 16 ASCII Characters for the part number Number of Pins 74 2 Number of pins used by the daughter board 12 Serial number of the board. This is a 12 character string which is: WWYY4P13nnnn where: WW = 2 digit week of the year of production YY = 2 digit year of production nnnn = incrementing board number Serial Number 76 Two bytes for each configurable 74 pins on the expansion connectors 88 148 VDD_3V3EXP Current 236 2 Maximum current in milliamps VDD_5V Current 238 2 Maximum current in milliamps SYS_5V Current 240 2 Maximum current in milliamps DC Supplied 242 2 Indicates whether or not the board is supplying voltage on the VDD_5V rail and the current rating 000=No 1-0xFFFF is the current supplied Available 244 32543 Available space for other non-volatile codes/data Pin Usage Bit 15………...Pin is used or not…………...0=Unused by Cape 1=Used by Cape Bit 14-13………Pin Direction……..1 0=Output 01=Input 11=BDIR Bits 12-7………Reserved Bit 6………….Slew Rate 0=Fast 1=Slow Bit 5………….Rx Enable…..0=Disabled 1=Enabled Bit 4………….Pull Up/Dn Select….0=Pulldown 1=PullUp Bit 3…………..Pull Up/DN enabled…..0=Enabled 1=Disabled Bits 2-0 ………Mux Mode Selection….Mode 0-7 Page 68 of 83 BeagleBone System Reference Manual REF: BBONE_SRM 8.1.4 RevA5.0.1 Pin Usage Table 15 is the locations in the EEPROM to set the I/O pin usage for the Cape. The table is left blank as a convenience and can be printed out and used as a template for creating a custom setting for each Cape. The 16 bit integers and all 16 bit fields are to be stored in big endian format. Bit 15 PIN USAGE is an indicator and should be a 1 if the pin is used or 0 if it is unused. Bits 14-7 RSERVED is not to be used and left as 0. Bit 6 SLEW CONTROL 0=Fast 1=Slow Bit 5 RX Enabled 0=Disabled 1=Enabled Bit 4 PU/PD 0=Pulldown 1=Pullup. Bit 3 PULLUP/DN 0=Pullup/pulldown enabled 1= Pullup/pulldown disabled Bit 2-0 MUX MODE SELECT Mode 0-7. Refer to TRM for proper settings The AIN0-6 pins do not have a pin mux setting, but they need to be set to indicate if each of the pins is used on the Cape. Only bit 15 is used. Table 15. 15 Off set Conn Name 88 P9-22 UART2_RXD 90 P9-21 UART2_TXD 92 P9-18 I2C1_SDA 94 P9-17 I2C1_SCL 96 P9-42 GPIO0_7 98 P8-35 UART4_CTSN 100 P8-33 UART4_RTSN 102 P8-31 UART5_CTSN 104 P8-32 UART5_RTSN 106 P9-19 I2C2_SCL 108 P9-20 I2C2_SDA 110 P9-26 UART1_RXD 112 P9-24 UART1_TXD 114 P9-41 CLKOUT2 116 P8-19 EHRPWM2A 118 P8-13 EHRPWM2B 120 P8-14 GPIO0_26 122 P8-17 GPIO0_27 Pin Usage EEPROM Pin Usage 14 13 Type 12 11 10 9 8 7 6 5 4 3 Reserved P P S U U L R / E X D P W E D N Page 69 of 83 2 1 0 Mux Mode BeagleBone System Reference Manual REF: BBONE_SRM 15 Off set Conn Name 124 P9-11 UART4_RXD 126 P9-13 UART4_TXD 128 P8-25 GPIO1_0 130 P8-24 GPIO1_1 132 P8-5 GPIO1_2 134 P8-6 GPIO1_3 136 P8-23 GPIO1_4 138 P8-22 GPIO1_5 140 P8-3 GPIO1_6 142 P8-4 GPIO1_7 P8-12 GPIO1_12 146 P8-11 GPIO1_13 148 P8-16 GPIO1_14 150 P8-15 GPIO1_15 152 P9-15 GPIO1_16 154 P9-23 GPIO1_17 156 P9-14 EHRPWM1A 158 P9-16 EHRPWM1B 160 P9-12 GPIO1_28 162 P8-26 GPIO1_29 164 P8-21 GPIO1_30 166 P8-20 GPIO1_31 168 P8-18 GPIO2_1 170 P8-7 TIMER4 172 P8-9 TIMER5 174 P8-10 TIMER6 176 P8-8 TIMER7 178 P8-45 GPIO2_6 180 P8-46 GPIO2_7 182 P8-43 GPIO2_8 184 P8-44 GPIO2_9 186 P8-41 GPIO2_10 188 P8-42 GPIO2_11 190 P8-39 GPIO2_12 192 P8-40 GPIO2_13 144 Pin Usage 14 13 Type 12 11 10 9 8 7 6 5 4 3 Reserved P P S U U L R / E X D P W E D N Page 70 of 83 RevA5.0.1 2 1 0 Mux Mode BeagleBone System Reference Manual REF: BBONE_SRM 15 Off set Conn Name 194 P8-37 UART5_TXD 196 P8-38 UART5_RXD 198 P8-36 UART3_CTSN 200 P8-34 UART3_RTSN 202 P8-27 GPIO2_22 204 P8-29 GPIO2_23 206 P8-28 GPIO2_24 208 P8-30 GPIO2_25 210 P9-29 SPI1_D0 212 P9-30 SPI1_D1 214 P9-28 SPI1_CS0 216 P9-27 GPIO3_19 218 P9-31 SPI1_SCLK 220 P9-25 GPIO3_21 222 P9-39 AIN0 224 P9-40 AIN1 226 P9-37 AIN2 228 P9-38 AIN3 230 P9-33 AIN4 232 P9-36 AIN5 234 P9-35 AIN6 8.1.5 14 13 Pin Usage Type 12 11 10 9 8 7 6 5 4 3 Reserved P P S U U L R / E X D P W E D N RevA5.0.1 2 1 0 Mux Mode EEPROM Write Protect The design in Figure 28 does not have the write protect enabled. This allows the EEPROM to be used for storing application information based on the board’s functions. It also allows the EEPROM to be reconfigured to meet future EEPROM format changes as things evolve. Page 71 of 83 REF: BBONE_SRM 8.2 BeagleBone System Reference Manual RevA5.0.1 Expansion Connectors A combination of male and female headers is used for access to the expansion headers on the main board. There are three possible mounting configurations for the expansion headers: • • • Single-no board stacking but can be used on the top of the stack. Stacking-up to four boards can be stacked on top of each other. Stacking with signal stealing-up to three boards can be stacked on top of each other, but certain boards will not pass on the signals they are using to prevent signal loading or use by other cards in the stack. The following sections describe how the connectors are to be implemented and used for each of the different configurations. NOTE: Be careful if you are considering using standoffs on the BeagleBone. The mounting hole next to the DC power jack has resistors that are a little too close to the hole and if you are not careful, you can damage those resistors when attaching the standoff. Use as small a diameter standoff as possible. 8.2.1 Non-Stacking Headers-Single Cape For non-stacking Capes single configurations or where the Cape can be the last board on the stack, the two 46 pin expansion headers use the same connectors. Figure 29 is a picture of the connector. These are dual row 23 position 2.54mm x 2.54mm connectors. Figure 29. Single Expansion Connector The connector is typically mounted on the bottom side of the board as shown in Figure 30. These are very common connectors and should be easily located. You can also use two single row 23 pin headers for each of the dual row headers. Page 72 of 83 REF: BBONE_SRM BeagleBone System Reference Manual RevA5.0.1 Figure 30. Single Cape Expansion Connector It is allowed to only populate the pins you need. As this is a non-stacking configuration, there is no need for all headers to be populated. This can also reduce the overall cost of the Cape. This decision is up to the Cape designer. For convenience listed in Table 15 are some possible choices for part numbers on this connector. They have varying pin lengths and some may be more suitable than others for your use. It should be noted, that the longer the pin and the further it is inserted into the BeagleBone connector, the harder it will be to remove due to the tension on 92 pins. This can be minimized by using shorter pins or removing those pins that are not used by your particular design. The minimum the pin length can be is .125(3.175mm) in order to insure connection to the pins in the connector on the BeagleBone. Table 16. SUPPLIER Major League Major League Major League Single Cape Connectors PARTNUMBER TSHC-123-D-03-145-GT-LF TSHC-123-D-03-240-GT-LF TSHC-123-D-03-255-GT-LF TAIL LENGTH(in) TAIL LENGTH(mm) .145 .240 .255 3.68 6.10 6.47 The GT in the part number is a plating option. Other options may be used as well as long as the contact area is gold. Other possible sources are Sullins and Samtec for these connectors. 8.2.2 Battery Connector- Single For non-stacking or single configuration this connector is a single 10 pin expansion header. Figure 31 is a picture of the connector. This is a dual row 10 position 2.54mm x 2.54mm connectors. This is the same connector as the main connectors, only shorter. Figure 31. Battery/Backlight Expansion Connector Page 73 of 83 BeagleBone System Reference Manual REF: BBONE_SRM RevA5.0.1 Table 18 below is the possible part numbers for this connector. Table 17. SUPPLIER Major League Major League Major League 8.2.3 Single Cape Backlight Connectors PARTNUMBER TAIL LENGTH(in) TAIL LENGTH(mm) .145 .240 .255 3.68 6.10 6.47 TSHC-105-D-03-145-GT-LF TSHC-105-D-03-240-GT-LF TSHC-105-D-03-255-GT-LF Main Expansion Headers-Stacking For stacking configuration, the two 46 pin expansion headers use the same connectors. Figure 32 is a picture of the connector. These are dual row 23 position 2.54mm x 2.54mm connectors. Figure 32. Expansion Connector The connector is mounted on the top side of the board with longer tails to allow insertion into the BeagleBone. Figure 33 is the connector configuration for the connector. Figure 33. Stacked Cape Expansion Connector For convenience listed in Table 17 are some possible choices for part numbers on this connector. They have varying pin lengths and some may be more suitable than others for your use. It should be noted, that the longer the pin and the further it is inserted into the BeagleBone connector, the harder it will be to remove due to the tension on 92 pins. This can be minimized by using shorter pins. There are most likely other suppliers out there that will work for this connector as well. If anyone finds other suppliers of compatible connectors that work, let us know and they will be added to this document. The minimum length of the pin that inserts into the BeagleBone connector is .125 (3.175mm). Page 74 of 83 BeagleBone System Reference Manual REF: BBONE_SRM Table 18. RevA5.0.1 Stacked Cape Connectors SUPPLIER PARTNUMBER TAIL LENGTH(in) TAIL LENGTH(mm) Major League Major League Major League SSHQ-123-D-06-GT-LF SSHQ-123-D-08-GT-LF SSHQ-123-D-10-GT-LF .190 .390 .560 4.83 9.91 14.22 There are also different plating options on each of the connectors above. Gold plating on the contacts is the minimum requirement. If you choose to use a different part number for plating or availability purposes, make sure you do not select the “LT” option. Other possible sources are Sullins and Samtec. 8.2.4 Battery Connector Stacking This connector is a single two 10 pin expansion header. Figure 34 is a picture of the connector. This is a dual row 10 position 2.54mm x 2.54mm connector and is the same as the main connector except with less positions. Figure 34. Stacked Battery Expansion Connector For convenience listed in Table 18 are some possible choices for part numbers on this connector. They have varying pin lengths and some may be more suitable than others for your use. Table 19. Stacked Cape Connectors SUPPLIER PARTNUMBER TAIL LENGTH(in) TAIL LENGTH(mm) Major League Major League Major League SSHQ-105-D-06-GT-LF SSHQ-105-D-08-GT-LF SSHQ-105-D-10-GT-LF .190 .390 .560 4.83 9.91 14.22 Tail length does not include the thickness of the Cape PCB. 8.2.5 Stacked Capes w/Signal Stealing Figure 35 is the connector configuration for stackable Capes that does not provide all of the signals upwards for use by other boards. This is useful if there is an expectation that other boards could interfere with the operation of your board by exposing those signals Page 75 of 83 BeagleBone System Reference Manual REF: BBONE_SRM RevA5.0.1 for expansion. This configuration consists of a combination of the stacking and nonstacking style connectors. Figure 35. Stacked w/Signal Stealing Expansion Connector 8.3 Signal Usage Based on the pin muxing capabilities of the processor, each expansion pin can be configured for different functions. When in the stacking mode, it will be up to the user to insure that any conflicts are resolved between multiple stacked cards. When stacked, the first card detected will be used to set the pin muxing of each pin. This will prevent other modes from being supported on stacked cards and may result in them being inoperative. In Section 7.12 of this document, the functions of the pins are defined as well as the pin muxing options. Refer to this section for more information on what each pin is. To simplify things, if you use the default name as the function for each pin and use those functions, it will simplify board design and reduce conflicts with other boards. Interoperability is up to the board suppliers and the user. This specification does not specify a fixed function on any pin and any pin can be used to the full extent of the functionality of that pin as enabled by the processor. 8.4 Cape Power This section describes the power rails for the Capes and their usage. 8.4.1 Main Board Power The Table 19 describes the voltages from the main board that are available on the expansion connectors and their ratings. All voltages are supplied by connector P9. The current ratings listed are per pin. Table 20. Current Expansion Voltages Name P9 Name Current GND 1 2 GND 250mA VDD_3V3EXP 3 4 VDD_3V3EXP 250mA 1000mA VDD_5V 5 6 VDD_5V 1000mA Page 76 of 83 REF: BBONE_SRM 250mA BeagleBone System Reference Manual SYS_5V 7 8 SYS_5V : : GND 43 44 GND GND 45 46 GND RevA5.0.1 250mA The VDD_3V3EXP rail is supplied by the LDO on the BeagleBone and is the primary power rail for expansion boards. VDD_5V is the main power supply from the DC input jack. This voltage is not present when the board is powered via USB. The amount of current supplied by this rail is dependent upon the amount of current available. Based on the board design, this rail is limited to 1A per pin from the main board. The SYS_5V rail is the main rail for the regulators on the main board. When powered from a DC supply or USB, this rail will be 5V. The available current from this rail depends on the current available from the USB and DC external supplies. 8.4.2 Expansion Board External Power A Cape can have a jack or terminals to bring in whatever voltages may be needed by that board. Care should be taken not to let this voltage feedback into any of the expansion header pins. It is possible to provide 5V to the main board from an expansion board. By supplying a 5V signal into the VDD_5V rail, the main board can be supplied. This voltage must not exceed 5V. You should not supply any voltage into any other pin of the expansion connectors. Based on the board design, this rail is limited to 1A per pin to the BeagleBone. 8.4.3 Mechanical This section provides the guidelines for the creation of expansion boards from a mechanical standpoint. Defined is a standard board size that is the same profile as the BeagleBone. It is expected that the majority of expansion boards created will be of standard size. It is possible to create boards of other sizes and in some cases this is required, as in the case of an LCD larger than the BeagleBone board. 8.4.4 Standard Cape Size Figure 36 is the outline of the standard Cape. The dimensions are in inches. Page 77 of 83 REF: BBONE_SRM BeagleBone System Reference Manual RevA5.0.1 Figure 36. Cape Board Dimensions A slot is provided for the Ethernet connector to stick up higher than the Cape when mounted. This also acts as a key function to insure that the Cape is oriented correctly. Space is also provided to allow access to the user LEDs and reset button on the main board. 8.4.5 Extended Cape Size Capes larger than the standard board size are also allowed. A good example would be an LCD panel. There is no practical limit to the sizes of these types of boards. The notch for the key is also not required, but it is up to the supplier of these boards to insure that the BeagleBone is not plugged in incorrectly in such a manner that damage would be cause to the BeagleBone or any other Capes that may be installed. Any such damage will be the responsibility of the supplier of such a Cape to repair. As with all Capes, the EEPROM is required and compliance with the power requirements must be adhered to. Page 78 of 83 REF: BBONE_SRM 9.0 BeagleBone System Reference Manual RevA5.0.1 Board Setup This section describes how to setup the board and to make sure that it is operating. It also provides an advanced section that allows you to run a self diagnostic test that does require additional equipment to be purchased. 9.1 Creating A SD Card If you need to create an SD card for the board that is the same as what ships with the BeagleBone, you can follow the instructions found at the following location: http://circuitco.com/support/index.php?title=BeagleBone Other methods are also possible if you are familiar with Linux. Instructions are found at the following link which also will have the latest image. http://www.angstrom-distribution.org/demo/beaglebone/ You will need a 4GB microSD card. 9.2 USB Powered Setup The board ships with everything you need for this configuration. • • • BeagleBone microSD card with bootable SW USB Type A to 5 pin connector To setup the board: 1) 2) 3) 4) 5) 6) Insert the SD card into the SD card connector Plug the USB cable into the BeagleBone Plug the other end of the USB cable into the PC USB port. The power LED D1 should be on After a few seconds, USER0 and USER1 LED should start flashing After 10 seconds or so, the board should show up as a mass storage device on your PC 7) Open the new drive and click on the Readme.html file. 8) The file should open in your browser. 9) Follow the instructions on the HTML page. 9.3 DC Powered Setup Page 79 of 83 REF: BBONE_SRM BeagleBone System Reference Manual RevA5.0.1 The board ships with everything you need for this configuration except for a power supply. The first three items below are provided and the power supply will need to be provided by you. • • • • BeagleBone microSD card with bootable SW USB Type A to 5 pin connector 5VDC 1A power supply w/2.1mm x 5.5mm connector, center positive. To setup the board: 1) 2) 3) 4) 5) 6) 7) Insert the SD card into the SD card connector Plug the DC cable into the board. The power LED D1 should be on Plug the USB cable into the BeagleBone Plug the other end of the USB cable into the PC USB port. After a few seconds, USER0 and USER1 LED should start flashing After 10 seconds or so, the board should show up as a mass storage device on your PC 8) Open the new drive and click on the Readme.html file. 9) The file should open in your browser. 10) Follow the instructions on the HTML page. 9.4 Advanced Test This test involves the purchase of a USB hub that is equipped with an Ethernet port or the use of a USB Hub with a USB to Ethernet Dongle plugged in. The SW that ships with the board is capable of running this test. You may need to load drivers for your particular Hub or Ethernet dongle. The following procedure will setup and test the board. The following items are tested on the board: • • • • • • • • • • • • USB Client Port USB Host Port Ethernet Port DDR PMIC EEPROM Processor SD Slot DC Power USB HUB USB to Serial LEDs Page 80 of 83 REF: BBONE_SRM 9.4.1 BeagleBone System Reference Manual RevA5.0.1 Equipment Needed The following items are needed to perform this test: 1) 2) 3) 4) 5) 6) 9.4.2 USB Hub with Ethernet port Ethernet Cable USB A Male to 5pin male BeagleBone 26 AWG jumper wire, stripped 5VDC 1A power supply, 2.1mm Center positive Procedure 1) 2) 3) 4) 5) Connect the USB HUB to the USB Host port of the BeagleBone. Connect the HUB Ethernet port to the BeagleBone Ethernet port. Connect one of the USB ports to USB connector on the BeagleBone. Insert the SD card that came with the board into the SD connector. Add a jumper wire between pin 2 and 3 of the P8. This tells the SW to run the test. 6) Insert the DC power supply 7) The PWR LED should turn on. 8) Then D2 and D3 should start flashing indicating the boot process has begun. 9) After about a minute, D2 and D3 should turn off and D5 should start flashing. 10) D5 will continue to flash during the test process which should take about 2-3 minutes. 11) At the end of the test one of two things will happen: a. If all the LEDS are on solid, then the board has passed the test. b. If all LEDS are flashing, then the board has failed the test. 9.4.3 Debugging It is possible to add a USB to serial cable to the HUB for messages as the tests run. This will tell you where the test fails. It will require a USB to serial adapter to also be plugged into your PC and a Null modem female to female adapter be placed between the two cables. In order for this to work, the Linux driver needs to be installed on the BeagleBone for the USB to serial adapter. For now, only one USB to serial adapter is supported. Others will be added over time. Once you have the correct cable configuration, you can open up a terminal program set to the serial port and set for 115KBaud, 8,n2 and no handshaking. The results of the test as run will be printed to the terminal. Page 81 of 83 BeagleBone System Reference Manual REF: BBONE_SRM 10.0 BeagleBone Mechanical Specification Size: Max height: PCB Layers: PCB thickness: RoHS Compliant: Weight: 3.5” x 2.1” (86.36mm x 53.34mm) .187” (4.76mm) 6 .062” Yes 1.4 oz Figure 37. Board Top Profile Figure 38. Board Bottom Profile Page 82 of 83 RevA5.0.1 REF: BBONE_SRM BeagleBone System Reference Manual RevA5.0.1 11.0 Design Information Design information can be found on the SD card that ships with board under the documents/hardware directory when connected over the USB cable. Provided there is: • • • • • • Schematic in PDF Schematic in OrCAD (Cadence Design Entry CIS 16.3) PCB Gerber PCB Layout File (Allero) Bill of Material System Reference Manual (This document). You can also download the files from http://beagleboard.org/hardware/design .or from the CircuitCo WIKI at http://circuitco.com/support/index.php?title=BeagleBone ALL support for this design is through the BeagleBoard.org community at beagleboard@googlegroups.com . There are also some community members working to convert the schematics and PCB files into other formats. Look for those to available in the future. Page 83 of 83