at88sc0104c ATMEL Corporation, at88sc0104c Datasheet - Page 28

• Manufacturer Part Number: at88sc0104c
• Description: Cryptomemory Specification For Standard Mode Of Operation
• Manufacturer: ATMEL Corporation

7. Synchronous Protocol
7.1
7.2
24
Start-up Sequence
Command Set
AT88SC0104/0204/0404/0808/1616/3216/6416/12816/25616C
Smart card applications that support the 2-Wire protocol can also use CryptoMemory in the syn-
chronous mode.
Communication with the CryptoMemory using the synchronous protocol is very similar to com-
munication with AT24Cxxx Serial EEPROM devices using a two-wire protocol (TWI). Basic
command structure and timing are the same however a significant difference exists when read-
ing the CryptoMemory device that will be described below.
When first powering up the device, 5 pulses are required on CLK-SCL for reading of internal reg-
isters. This may be accomplished by sending one full command byte to the device. The device
will not respond but will then be ready to respond to the next correct command sequence.
The command set of CryptoMemory is expanded compared to a Serial EEPROM as the func-
tionality of CryptoMemory exceeds that of a simple memory device. Each instruction sent to the
CryptoMemory must have 4 bytes: Command, Address 1, Address 2 and N. The last byte, N,
defines the number of any additional data bytes to be sent or received from the CryptoMemory
device.
• Power-up V
• External pull-up resistor pulls I/O-SDA high with V
• After stable V
• CLK-SCL and I/O-SDA may be driven.
CLK-SCL
I/O-SDA
V cc
CC
CC
, 5 pulses are applied to CLK-SCL
1
2
3
4
CC
5
5210A–SMIC–04/07