AT88SC0404CA-TU Atmel, AT88SC0404CA-TU Datasheet - Page 13
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AT88SC0404CA-TU
Manufacturer Part Number
AT88SC0404CA-TU
Description
Manufacturer
Atmel
Datasheet
1.AT88SC0404CA-TU.pdf
(22 pages)
Specifications of AT88SC0404CA-TU
Operating Temperature (max)
85C
Operating Temperature (min)
-40C
Mounting
Surface Mount
Pin Count
8
Operating Temperature Classification
Industrial
Lead Free Status / RoHS Status
Compliant
12.2
Figure 1. Write Lock Example
12.3
12.4
5203AS–CRYPT–6/08
Address
$080
Write Lock
Password Verification
Authentication Protocol
11011001
$0
If a user zone is configured in the write lock mode, the lowest address byte of an 8-byte page
constitutes a write access byte for the bytes of that page. For example, the write lock byte at
$080 controls the bytes from $081 to $087.
The Write-Lock byte itself may be locked by writing its least significant (rightmost) bit to “0”.
Moreover, when write lock mode is activated, the write lock byte can only be programmed – that
is, bits written to “0” cannot return to “1”.
In the write lock configuration, write operations are limited to writing only one byte at a time.
Passwords may be used to protect READ and/or WRITE access of any user zone. When a valid
password is presented, it is memorized and active until power is turned off, unless a new pass-
word is presented or RST becomes active. There are eight password sets that may be used to
protect any user zone. Only one password is active at a time.
Presenting the correct WRITE password also grants READ access privileges.
The access to a user zone may be protected by an authentication protocol. Any one of four keys
may be selected to use with a user zone.
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 vali-
dated, the card loses its previous authentication which must be presented again to gain access.
Only the latest request is memorized.
xxxx xxxx
locked
$1
xxxx xxxx
locked
$2
xxxx xxxx
$3
AT88SC0404CA [Preliminary]
xxxx xxxx
$4
xxxx xxxx
locked
$5
xxxx xxxx
$6
xxxx xxxx
$7
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