AT88SC0104CA_11 ATMEL [ATMEL Corporation], AT88SC0104CA_11 Datasheet - Page 24

• Manufacturer Part Number: AT88SC0104CA_11
• Description: Atmel CryptoMemory Specification Datasheet
• Manufacturer: ATMEL [ATMEL Corporation]

7.
7.1
Protocol Selection
CryptoMemory supports two application areas with different communication protocols:
The power-up sequence of CryptoMemory determines what mode it shall operate in. A brief description of each of these
modes follows.
Synchronous Mode for Embedded Applications
The two-wire serial interface is used for fast and efficient communication with logic and controllers. The synchronous mode is
the default after powering up V
CryptoMemory in standard plastic packages RST is not bonded out and this is the only communication protocol.
Figure 7-1. Asynchronous Mode
CLK-SCL
The asynchronous mode is selected when RST is low on a rising edge of CLK. Once the asynchronous mode has been
selected, it is not possible to return to the synchronous mode other than by powering the device off and on again.
I/O-SDA
•
•
•
•
•
RST
V cc
Two-wire serial communication for embedded applications
ISO 7816 asynchronous T=0 smart card interface
Power-up V
After stable V
CLK-SCL and I/O-SDA may then be driven
CC
CC
, RST goes high also
, apply five pulses CLK-SCL
1
CC
due to the internal and/or external pull-up on RST. For embedded applications using
2
3
Atmel AT88SC0104CA/0204CA/0404CA/0808CA [Datasheet]
4
5
8664E−CRYPTO−12/11
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