AT88SC0808CA View Datasheet(PDF) - Atmel Corporation
Part Name
Description
MFG CO.
'AT88SC0808CA' PDF : 23 Pages View PDF
12.
Protocol Selection
The AT88SC0808CA supports two different communication protocols.
• Smartcard Applications:
Smartcard applications use ISO 7816-B protocol in asynchronous T = 0 mode for compatibility and interoperability
with industry standard smartcard readers.
• Embedded Applications:
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.
12.1
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.
• Power-up VCC, RST goes high also
• After stable VCC, SCL(CLK) and SDA(I/O) may be driven
• Once synchronous mode has been selected, it is not possible to switch to asynchronous mode without first powering
off the device
Figure 12-1. Synchronous Two-wire Protocol
Vcc
I/O-SDA
RST
CLK-SCL
1 2345
Note:
Five clock pulses must be sent before the first command is issued.
Atmel AT88SC0808CA [Summary DATASHEET]
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