2.3. Clock generation and Frequency U.K.
TCS_06The card shall operate within a frequency range of 1 to 5 MHz and may support higher frequencies. Within one card session the clock frequency may vary ± 2 %. The clock frequency is generated by the Vehicle Unit and not the card itself. The duty cycle may vary between 40 and 60 %.U.K.
TCS_07Under conditions contained into the card file EF ICC, the external clock can be stopped. The first byte of the EF ICC file body codes the Clockstop mode conditions:U.K.
| Low | High | ||
|---|---|---|---|
| Bit 3 | Bit 2 | Bit 1 | |
| 0 | 0 | 1 | Clockstop allowed, no preferred level |
| 0 | 1 | 1 | Clockstop allowed, high level preferred |
| 1 | 0 | 1 | Clockstop allowed, low level preferred |
| 0 | 0 | 0 | Clockstop not allowed |
| 0 | 1 | 0 | Clockstop only allowed on high level |
| 1 | 0 | 0 | Clockstop only allowed on low level |
Bits 4 to 8 are not used.