ATSHA204 ATMEL [ATMEL Corporation], ATSHA204 Datasheet - Page 45

• Manufacturer Part Number: ATSHA204
• Description: Atmel CryptoAuthentication
• Manufacturer: ATMEL [ATMEL Corporation]

8.7
Lock Command
Write either LockConfig or LockValue to 0xFF, thereby changing the permissions in the designated zone.
This command fails if the designated zone is already locked.
Prior to locking the device, the ATSHA204 uses the CRC-16 algorithm to generate a summary digest of the designated
zone(s). The calculation is made identically to the CRC computed over the input and output blocks.
If the input summary does not match that computed on the device, an error is returned and the personalization process should
be repeated.
Table 8-20. Input Parameters
Table 8-21. Output Parameter
Opode
Param1
Param2
Data
Name
Success
•
•
For the configuration zone, the CRC is calculated over all 88 bytes.
For the data and OTP zones, their contents are concatenated in that order to create the input to the CRC algorithm.
Name
LOCK
Zone
Summary
-
Size
Size
1
1
1
2
0
Notes
Upon successful execution, the Atmel ATSHA204 returns a value of zero.
Notes
0x17
Bit 0: Zero for config zone, 1 for data and OTP zones.
Bits 1-6: Must be zero.
Bit 7: If one, the check of the zone CRC is ignored and the zone is locked, regardless
Summary of the designated zones, or should be 0x0000 if Zone[7] is set.
-
of the state of the memory. Atmel does not recommend using this mode.
Atmel ATSHA204 [DATASHEET]
8740D−CRYPTO−3/12
45