CTRLC

Control C

  0x08 32 PAC Write-Protection, Enable-Protected 0x00000000  
Parent topic: Register Description

Control C

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

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

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.

ValueDescription
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

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.

ValueDescription
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

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.