Texas Instruments SHA-1/HMAC BASED SECURITY AND AUTHENTICATION IC BQ26100EVM BQ26100EVM Datenbogen
Produktcode
BQ26100EVM
www.ti.com
Volatile Register Memory
A = A + 1
ROM
Function
Flow
Master TX:
16-bit address, A
16-bit address, A
Master RX:
CRC of M/F cmd & A
CRC of M/F cmd & A
Master RX:
D
D
Master RX:
8-bit data @ A
8-bit data @ A
A = 0x0013?
YES
Read
Digest
Flow
M/F = 0xDD
NO
A = 0x0013?
NO
ROM
Function
Flow
Master RX:
CRC of preloaded
A[7:0] & shifted D
CRC of preloaded
A[7:0] & shifted D
YES
Write
Message
Flow
M/F = 0x22
Master TX:
16-bit address, A
16-bit address, A
A = A +1
Master RX:
CRC of all data transmitted
CRC of all data transmitted
Master RX:
CRC of M/F cmd, A & D
CRC of M/F cmd, A & D
Master TX:
8-bit data, D
8-bit data, D
Master TX:
8-bit data, D
8-bit data, D
CRC = A[7:0]
(1)
(1)
SLUS696A – JUNE 2006 – REVISED FEBRUARY 2007
The register memory is intended for in-field programming.
Message and Digest Registers – Memory Function Command 0xDD (Read) and 0x22 (Write)
The message is a 160-bit input to the HMAC calculation, and the digest is the 160-bit output of the HMAC
calculation. The message and digest share the same memory space, meaning that the message cannot be
read back once the digest has been computed. The MSB of the message should be written to address
0x0013, and the LSB written to address 0x0000. The digest overwrites the message in the following manner.
The message is a 160-bit input to the HMAC calculation, and the digest is the 160-bit output of the HMAC
calculation. The message and digest share the same memory space, meaning that the message cannot be
read back once the digest has been computed. The MSB of the message should be written to address
0x0013, and the LSB written to address 0x0000. The digest overwrites the message in the following manner.
Table 5. Message/Digest Space Addressing
ADDRESS
MESSAGE VALUE
DIGEST VALUE
0x0013 – 0x0010
M[159:128]
A[31:0]
0x000F – 0x000C
M[127:96]
B[31:0]
0x000B – 0x0008
M[95:64]
C[31:0]
0x0007 – 0x0004
M[63:32]
D[31:0]
0x0003 – 0x0000
M[31:0]
E[31:0]
NOTE:
See the SHA-1 and HMAC descriptions for more information on the meaning of the
variables in the above table.
variables in the above table.
(1)
16-Bit address is sent with lower 8-bit address followed by higher 8-bit address with least significant bit first.
Figure 10. Message/Digest Write/Read Flows
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