35.8.3 Control C
| Name: | CTRLC |
| Offset: | 0x08 |
| Reset: | 0x00000000 |
| Property: | PAC Write-Protection, Enable-Protected |
| Bit | 31 | 30 | 29 | 28 | 27 | 26 | 25 | 24 | |
| Access | |||||||||
| Reset |
| Bit | 23 | 22 | 21 | 20 | 19 | 18 | 17 | 16 | |
| MAXITER[2:0] | DSNACK | INACK | |||||||
| Access | R/W | R/W | R/W | R/W | R/W | ||||
| Reset | 0 | 0 | 0 | 0 | 0 | ||||
| Bit | 15 | 14 | 13 | 12 | 11 | 10 | 9 | 8 | |
| Access | |||||||||
| Reset |
| Bit | 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 | |
| GTIME[2:0] | |||||||||
| Access | R/W | R/W | R/W | ||||||
| Reset | 0 | 0 | 0 | ||||||
Bits 22:20 – MAXITER[2:0] Maximum Iterations
These bits define the maximum number of retransmit iterations.
These bits also define the successive NACKs sent to the remote transmitter when CTRLC.DSNACK is set.
This field is only valid when using ISO7816 T = 0 mode (CTRLA.MODE = 0x7).
Bit 17 – DSNACK Disable Successive Not Acknowledge
This bit controls how many times NACK will be sent on parity error reception.
This bit is only valid in ISO7816 T=0 mode and when CTRLC.INACK=0.
| Value | Description |
|---|---|
| 0 | NACK is sent on the ISO line for every parity error received. |
| 1 | Successive parity errors are counted up to the value specified in CTRLC.MAXITER. These parity errors generate a NACK on the ISO line. As soon as this value is reached, no additional NACK is sent on the ISO line. |
Bit 16 – INACK Inhibit Not Acknowledge
This bit controls whether a NACK is transmitted when a parity error is received.
This bit is only valid in ISO7816 T = 0 mode.
| Value | Description |
|---|---|
| 0 | NACK is transmitted when a parity error is received. |
| 1 | NACK is not transmitted when a parity error is received. |
Bits 2:0 – GTIME[2:0] Guard Time
These bits define the guard time when using RS485 mode (CTRLA.FORM = 0x0 or CTRLA.FORM = 0x1, and CTRLA.TXPO = 0x3) or ISO7816 mode (CTRLA.FORM = 0x7).
For RS485 mode, the guard time is programmable from 0-7 bit times and defines the time that the transmit enable pin (TE) remains high after the last stop bit is transmitted and there is no remaining data to be transmitted.
For ISO7816 T = 0 mode, the guard time is programmable from 2-9 bit times and defines the guard time between each transmitted byte.