beaglebone-black - Flipbook - Page 86
BeagleBone Black
Variable & MAC Memory VDD_3V3B
Fig. 8.2: Expansion Board EEPROM Write Protect
8.1.6 EEPROM Data Format
Table below shows the format of the contents of the expansion board EEPROM. Data is stored in Big Endian
with the least signi昀椀cant value on the right. All addresses read as a single byte data from the EEPROM, but two
byte addressing is used. ASCII values are intended to be easily read by the user when the EEPROM contents
are dumped.
Name
O昀昀set
Size (bytes)
Contents
Header
EEPROM Revision
Board Name
Version
Manufacturer
Part Number
Number of Pins
Serial Number
Pin Usage
VDD_3V3B Current
VDD_5V Current
SYS_5V Current
DC Supplied
Available
0
4
6
38
42
58
74
76
88
236
238
240
242
244
4
2
32
4
16
16
2
12
148
2
2
2
2
32543
0xAA, 0x55, 0x33, 0xEE
Revision number of the overall format of this EEPROM in ASCII =A1
Name of board in ASCII so user can read it when the EEPROM is dumped. Up to
Hardware version code for board in ASCII.Version format is up to the developer.i
ASCII name of the manufacturer. Company or individual’s name.
ASCII Characters for the part number. Up to maker of the board.
Number of pins used by the daughter board including the power pins used. Dec
Serial number of the board. This is a 12 character string which is: WWYY&&&&
Two bytes for each con昀椀gurable pins of the 74 pins on the expansion connectors
Maximum current in milliamps. This is HEX value of the current in decimal 1500
Maximum current in milliamps. This is HEX value of the current in decimal 1500
Maximum current in milliamps. This is HEX value of the current in decimal 1500
Indicates whether or not the board is supplying voltage on the VDD_5V rail and
Available space for other non-volatile codes/data to be used as needed by the m
8.1.7 Pin Usage
Table 18 is the locations in the EEPROM to set the I/O pin usage for the cape. It contains the value to be written
to the Pad Control Registers. Details on this can be found in section 9.2.2 of the AM3358 Technical Reference
Manual, 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 昀椀elds 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 RESERVED 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.
8.1. BeagleBone Black Cape Compatibility
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