AT88SC0808CA-SH ATMEL [ATMEL Corporation], AT88SC0808CA-SH Datasheet - Page 14

• Manufacturer Part Number: AT88SC0808CA-SH
• Description: Atmel CryptoMemory
• Manufacturer: ATMEL [ATMEL Corporation]

12.
12.1
Protocol Selection
The AT88SC0808CA supports two different communication protocols.
Synchronous Two-wire Serial Interface
The synchronous mode is the default mode after power up. This is due to the presence of an internal pull-up on RST. For
embedded applications using CryptoMemory in standard plastic packages, this is the only available communication protocol.
Figure 12-1. Synchronous Two-wire Protocol
Note:
CLK-SCL
I/O-SDA
•
•
•
•
•
RST
V cc
Smartcard Applications:
Embedded Applications:
Power-up V
After stable V
Once synchronous mode has been selected, it is not possible to switch to asynchronous mode without first powering
Smartcard applications use ISO 7816-B protocol in asynchronous T = 0 mode for compatibility and interoperability
with industry standard smartcard readers.
A two-wire serial interface provides fast and efficient connectivity with other logic devices or microcontrollers.
The power-up sequence determines establishes the communication protocol for use within that power cycle. Protocol
selection is allowed only during power-up.
off the device
Five clock pulses must be sent before the first command is issued.
CC
CC
, RST goes high also
, SCL(CLK) and SDA(I/O) may be driven
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2
3
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Atmel AT88SC0808CA [Summary DATASHEET]
5204FS−CRYPTO−12/11
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