AT88SC0404CA-MJ Atmel, AT88SC0404CA-MJ Datasheet - Page 33

• Manufacturer Part Number: AT88SC0404CA-MJ
• Description: IC EEPROM 4KBIT 4MHZ M2J
• Manufacturer: Atmel
• Series: CryptoMemory®r

Specifications of AT88SC0404CA-MJ

• 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: 0°C ~ 70°C
• Package / Case: M2 J, Smart Card Module
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

8.8.
8.8.1. Functional
32
Figure 16. Write User Zone Command Structure
Random Read: $B1
Figure 17. Random Read Sequence Description
The Random Read command $B1 allows reading of data from the devices configuration memory or currently selected
user zone (The “System WRITE: $B4” section describes how to select a user zone).
The Random Read command provides the host ability to sequentially clock data from the device starting from a
specified address. The host needs to first specify the start address to read from in the memory by executing a “dummy”
operation. The host does this by clocking in the four bytes of the WRITE command and then follows them with a
START condition instead of a data byte. At this point, the device’s internal logic is pointing to the address from the
aborted WRITE operation. The host may then issue the Random Read command byte ($B1) to which the device will
respond with the EEPROM byte at the current address location and then increment the internal address by one. The
device will continue to sequentially send out bytes as long as the host keeps acknowledging each byte with an ACK.
During this operation the address will “roll over” from the last byte of the current zone to the first byte of the same zone.
The host terminates Random Read by issuing a NACK signal instead of an ACK.
Atmel AT88SC0104/0204/0404/0808/CA
S
A
R
T
T
Command
1011 0000
C
A
K
RANDOM READ COMMAND
Address 1
xxxx xxxx
Number of bytes N
WRITE Command
Address A1
Address A2
Host
A
C
K
Address 2
xxxx xxxx
A
C
K
xxxx xxxx
N
Device
Data
Data
…
C
A
K
d7--- ---d0
Data
N data bytes
A
C
K
Data x N
d7--- ---d0
A
C
K
O
8664C–CRYPT–01/10
S
P
T