at88sc0104c ATMEL Corporation, at88sc0104c Datasheet - Page 50

• Manufacturer Part Number: at88sc0104c
• Description: Cryptomemory Specification For Standard Mode Of Operation
• Manufacturer: ATMEL Corporation

8.5.5
8.5.5.1
Figure 8-10. Verify Password Command Functional Description
Figure 8-11. Verify Password
46
CLA
**
AT88SC0104/0204/0404/0808/1616/3216/6416/12816/25616C
Verify Password: $BA
Functional
3 password bytes
Command
INS :
$BA
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 :
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 attempts counter before verifying the password, to prevent attacks. If
the password is correct, the device memorizes this success, clears the pasword 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 access to the configuration memory is granted when person-
alizing the device
r = 0: Write password,
r = 1: Read password,
p2p1p0: Password set number.
Verify Password
000r 0p
P1
2
p
1
p
0
Password Index
Command
P2
**
Host
PW1
PW2
PW3
$03
P3
d
7
--- ---d
PW1
Device
0
Data Sent
d
15
PW2
--- ---d
8
5210A–SMIC–04/07
d
23
--- ---d
PW3
16