AT88SC0404CA-MP Atmel, AT88SC0404CA-MP Datasheet - Page 30

• Manufacturer Part Number: AT88SC0404CA-MP
• Description: IC EEPROM 4KBIT 4MHZ M2P
• Manufacturer: Atmel
• Series: CryptoMemory®r

Specifications of AT88SC0404CA-MP

• 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 P, Smart Card Module
• Operating Temperature (max): 70C
• Operating Temperature (min): 0C
• Operating Temperature Classification: Commercial
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

8664C–CRYPT–01/10
Random Read: $B1
The Random Read command provides the host ability to sequentially clock data from the device starting from a
specified address. The host needs to issue a “dummy” WRITE operation in order to specify the start address for the
Random Read. The host does this by clocking in the four bytes of the WRITE command and then follows them with a
START condition instead of a data byte. At this point, the device’s internal logic is pointing to the address from the
aborted WRITE operation. The host may then issue the Random Read command byte ($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.
Address “roll over” is from the last byte of the current zone to the first byte of that zone. The host terminates Random
Read by issuing a NACK signal instead of an ACK.
Figure 14. Random Read Command
Atmel
write location. The NACK response, however, does not affect the loading of the read address. The Random Read
command works for both Configuration and User Memory. It is important to implement the CryptoMemory read
commands as specified; otherwise CryptoMemory responses will cause contention on the bus with a host using
standard TWI protocol.
R
S
T
A
T
Command
xxxx xxx0
®
WRITE
CryptoMemory
A
C
K
0000 0000
Address 1
®
will NACK the N parameter of the dummy WRITE Operation if the write were issued to an illegal
A
C
K
0a6--- ---a0
Address 2
Atmel AT88SC0104/0204/0404/0808/CA
A
C
K
n7--- ---n0
N
N
A
C
K
C
S
A
R
A
K
T
T
Random Read
Command
xxxx 0001
Data
A
C
K
d7--- ---d0
Data
A
C
K
Data x N
d7--- ---d0
N
C
A
K
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O
S
T
P