AT88SC0404CA-Y6H-T Atmel, AT88SC0404CA-Y6H-T Datasheet - Page 50

• Manufacturer Part Number: AT88SC0404CA-Y6H-T
• Description: IC EEPROM 4KBIT 4MHZ 8MAP
• Manufacturer: Atmel
• Series: CryptoMemory®r

Specifications of AT88SC0404CA-Y6H-T

• Format - Memory: EEPROMs - Serial
• Memory Type: EEPROM
• Memory Size: 4K (512 x 8)
• Speed: 4MHz
• Interface: I²C, 2-Wire Serial
• Voltage - Supply: 2.7 V ~ 3.6 V
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 8-UDFN Exposed Pad
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

10.7.2. Write Config Zone
10.7.3. Write Fuses
10.7.4. Send Checksum
10.7.5. Set User Zone
8664C–CRYPT–01/10
The maximum number of bytes to write for each call of the WRITE command is $16 and corresponds to the EEPROM
page size. Each data byte within a page must only be loaded once. In anti-tearing mode the maximum value for N is
$08 for all devices.
If the address provided at P2 is an unauthorized address, the device will return the "Command Unauthorized" code
($69 $00) after it has received the header. Since access rights vary throughout the configuration zone, the host may
provide an authorized starting address, but a number of bytes that causes the device to reach unauthorized data. In
this case, the device will prevent the internal write cycle and no bytes will be written in the EEPROM. At the end of the
command the "Command Unauthorized" code ($69 $00) will be returned instead of $90 $00 to indicate that no write
cycle occurred.
Table 31. Fuse Bytes
The fuses may only be "programmed", that is written from '1' to '0'. The write fuses operation is only allowed after
successfully presenting the secure code (Write 7 password). The fuses must be blown sequentially: FAB must be
blown first, CMA may be blown only if FAB is ‘0’, and PER only if CMA is ‘0’. The SEC fuse is blown at the Atmel
factory to protect lot history information.
To write data to user zones that require Authentication or Encryption for write access (ER = “0”, AM [1:0] = “00”, “01”, or
“10” in the access register), the host should first carry out the write command $B0, after which the device will return a
special status word: $62 $00. At this point the memory is unchanged and the device is waiting for the host to provide a
valid checksum before initiating the write cycle. The host immediately sends the checksum it has computed using the
System WRITE command with P1 = $02. Only if the checksum is valid will the device initiate the write cycle.
Furthermore, if the device receives an incorrect checksum, it will clear the authentication privilege. After this command
the host must perform ACK polling.
Before reading and writing data in the user zones, the host should select a zone with this command. At this time the
host may choose whether anti-tearing should be active for this zone.
Table 32. System WRITE Command Structure
CLA
**
Fuse
CMA
SEC
FAB
PER
INS : Command
$B4
Fuse ID
$07
$06
$04
$00
Command Header
p
7
P1
--- p
0
Atmel AT88SC0104/0204/0404/0808/CA
p
7
P2
--- p
0
n
7
P3
--- n
0
d
Data(1)
7
--- ---d
0
Data Sent
...
...
d
Data(N)
7
--- ---d
49
0
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