at88sc018 ATMEL Corporation, at88sc018 Datasheet - Page 6

• Manufacturer Part Number: at88sc018
• Description: Cryptocompanion? Chip For Cryptomemory And Cryptorf
• Manufacturer: ATMEL Corporation

6
1.4.5.1. Command Input
Table 3.
If the command ordinal is legal, the AT88SC018 will ACK the command input and start processing. It takes a variable
amount of time to process the command, up to 20ms depending on the number of EEPROM pages to be written. If an
illegal command ordinal (≥0x15) is sent to the chip it will lock up for a “security delay”, then resume normal operation.
Refer to
Values in the Cmd byte are chosen from the table below:
Table 4.
CryptoCompanion Chip
0
1
2
3, …
Byte # Direction
WriteMemoryAuthorized
WriteMemoryEncrypted
ReadManufacturingID
ChallengeResponse
ReadMemoryDigest
IncrementCounter
Section 1.6.4.
EncryptPassword
To Slave
To Slave
To Slave
To Slave
ReadMemory
ReadCounter
WriteMemory
Encryption_1
Encryption_2
Command Input Byte Sequence
Cmd Byte Values
GetRandom
VerifyFlash
GrindBytes
Command
Startup
Crunch
Auth_1
Auth_2
Device
Address
Cmd
Size
Data
Clear
Lock
Name
Value
0x01
0x02
0x03
0x04
0x05
0x06
0x07
0x08
0x09
0x0A
0x0B
0x0C
0x0D
0x0E
0x0F
0x10
0x11
0x12
0x13
0x14
0x15
This byte selects a particular chip on the two wire bus. Bit 1 of this byte should be 0 to
indicate a command transfer to the AT88SC018. Bit 0 of this byte should be 0 to
indicate that the data bytes travel from the master to the slave (TWI write).
The ordinal of the command to be executed by the AT88SC018, from the table below.
The total number of bytes to follow this byte may be 0 in the case that there are no
operand bytes.
Operand bytes as specified in
Command Descriptions.
Description
5277C–CryptoCompanion–9/09