at88sc153 ATMEL Corporation, at88sc153 Datasheet - Page 10

• Manufacturer Part Number: at88sc153
• Description: 3 X 64 X 8 Secure Memory With Authentication
• Manufacturer: ATMEL Corporation

8.3
9. Command Definitions and Protocols
Table 9-1.
Note:
10
Description
Write EEPROM
Read EEPROM
Verify Password
Initialize Authentication
Verify Authentication
Write Fuse
Read Fuse
Authentication Protocol
r : Read/write password
p : Password set
AT88SC153
Device Commands
The access to an user zone may be protected by an authentication protocol in addition to pass-
word-dependent rights.
The authentication success is memorized and active as long as the chip is powered, unless a
new authentication is initialized or RST becomes active. If the new authentication request is not
validated, the card has lost its previous authentication and it should be presented again. Only
the last request is memorized.
The authentication verification protocol requires the host to perform an Initialize Authentication
command, followed by a Verify Authentication command.
The password and authentication may be presented at any time and in any order. If the trials
limit has been reached, i.e., the 8 bits of the attempts counter have been written, the password
verification or authentication process will not be taken into account.
The communications protocol is based on the popular two-wire serial interface. Note that the
most significant bit is transmitted first.
CS3
CS3
CS3
CS3
CS3
CS3
CS3
b7
CS2
CS2
CS2
CS2
CS2
CS2
CS2
b6
Chip Select
CS1
CS1
CS1
CS1
CS1
CS1
CS1
b5
CS0
CS0
CS0
CS0
CS0
CS0
CS0
b4
Command
b3
0
0
1
1
z
z
r
b2
p
0
1
0
1
z
z
Instruction
b1
0
0
1
1
1
1
1
1016E–SMEM–12/07
b0
0
1
1
0
0
0
0