PROTSEL=T_EQ_0, NACKDIS=ENABLED, SCIEN=SMART_CARD_INTERFACE
Smart Card Interface Control register. Enables and configures the Smart Card Interface feature.
| SCIEN | Smart Card Interface Enable. 0 (SMART_CARD_INTERFACE): Smart card interface disabled. 1 (ASYNCHRONOUS_HALF_DU): Asynchronous half duplex smart card interface is enabled. |
| NACKDIS | NACK response disable. Only applicable in T=0. 0 (ENABLED): A NACK response is enabled. 1 (DISABLED): A NACK response is inhibited. |
| PROTSEL | Protocol selection as defined in the ISO7816-3 standard. 0 (T_EQ_0): T = 0 1 (T_EQ_1): T = 1 |
| RESERVED | Reserved. |
| TXRETRY | When the protocol selection T bit (above) is 0, the field controls the maximum number of retransmissions that the USART will attempt if the remote device signals NACK. When NACK has occurred this number of times plus one, the Tx Error bit in the LSR is set, an interrupt is requested if enabled, and the USART is locked until the FIFO is cleared. |
| XTRAGUARD | When the protocol selection T bit (above) is 0, this field indicates the number of bit times (ETUs) by which the guard time after a character transmitted by the USART should exceed the nominal 2 bit times. 0xFF in this field may indicate that there is just a single bit after a character and 11 bit times/character |
| RESERVED | Reserved, user software should not write ones to reserved bits. The value read from a reserved bit is not defined. |