7.2 Asynchronous Mode for Smart Card Applications
The asynchronous T=0 protocol defined by ISO 7816-3 is used for compatibility with industry-standard smart card readers. Selecting this mode requires the following power-up sequence, which complies with ISO 7816-3 for a cold reset in smart card applications.
- Power up VCC; RST, IO-SDA and CLK-SCL are low.
- Set I/O-SDA to Receive mode.
- Provide a clock signal to CLK-SCL.
- RST goes high after 400 clock cycles.
The device will respond with a 64-bit ATR code, including historical bytes to indicate the memory density within the CryptoMemory® family. Once Asynchronous mode has been selected, it is not possible to switch to Synchronous mode without powering off the device.
|
Device |
TS |
T0 |
TA (1) |
TB (1) |
TD (1) |
TA (2) |
T1 |
T2 |
|---|---|---|---|---|---|---|---|---|
|
AT88SC0104CA |
$3B |
$B2 |
$11 |
$00 |
$10 |
$80 |
$00 |
$01 |
|
AT88SC0204CA |
$3B |
$B2 |
$11 |
$00 |
$10 |
$80 |
$00 |
$02 |
|
AT88SC0404CA |
$3B |
$B2 |
$11 |
$00 |
$10 |
$80 |
$00 |
$04 |
|
AT88SC0808CA |
$3B |
$B2 |
$11 |
$00 |
$10 |
$80 |
$00 |
$08 |
Smart card applications that support the Two-Wire protocol can also use CryptoMemory in Synchronous mode.