AT88SC0204C_14 Datasheet, PDF (59/79 Pages) ATMEL Corporation – Atmel CryptoMemory, 2-Kbit

9.4.9 Verify Password: $BA
9.4.9.1 Functional
Figure 9-7. Verify Command Functional Description
Host
Device
8-password bytes
Command
Password Index
PW1
PW2
PW3
Read password indices: $10 to $17 for passwords 0 to 7.
Write password indices: $00 to $07 for passwords 0 to 7.
Secure code index: $07 (equivalent to Write 7 Password).
Four password index bits “r” and “ppp” indicate the password to compare:
r = 0: Write password
r = 1: Read password
p2p1p0: Password set number
Table 9-14. Verify Password
Verify Password
Data Sent
CLA INS : Command
P1
P2
P3
PW1
PW2
PW3
**
$BA
000r 0p2p1p0
**
$30
d7--- ---d0
d15--- ---d8
d23--- ---d16
If the maximum number of trials has been exceeded, the device will return $69 $00 instead of the INS code, after receiving the
header, to indicate the command is unauthorized. The device decrements the associated password attempts counter before
verifying the password, to prevent attacks. If the password is correct, the device memorizes this success, clears the attempts
counter and returns $90 $00. If the password is wrong, the device simply returns $69 $00 after decrementing the attempts
count. The Write 7 Password is also known as the Secure Code and must be properly presented before write access to the
configuration memory is granted when personalizing the device.
AT88SC0104C/0204C/0404C/0808C/1616C/3216C/6416C/12816C/25616C [Datasheet]
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Atmel-5211E-CryptoMem-Full-Specification-Datasheet_022014