Slave Node Configuration

• Write TXEN and RXEN in US_CR to enable both the transmitter and the receiver.
• Write USART_MODE in US_MR to select the LIN mode and the slave node configuration.
• Write CD and FP in US_BRGR to configure the baud rate.
• Wait until LINID in US_CSR rises.
• Check LINISFE and LINPE errors.
• Read IDCHR in US_RHR.
• Write NACT, PARDIS, CHKDIS, CHKTYPE, DLCM and DLC in US_LINMR to configure the frame transfer.

IMPORTANT: If the NACT configuration for this frame is PUBLISH, the US_LINMR must be written with NACT = PUBLISH even if this field is already correctly configured, in order to set the TXREADY flag and the corresponding write transfer request.

What comes next depends on the NACT configuration:

• Case 1: NACT = PUBLISH, the LIN controller sends the response
  • Wait until TXRDY in US_CSR rises.
  • Write TCHR in US_THR to send a byte.
  • If all the data have not been written, redo the two previous steps.
  • Wait until LINTC in US_CSR rises.
  • Check the LIN errors.
• Case 2: NACT = SUBSCRIBE, the USART receives the response
  • Wait until RXRDY in US_CSR rises.
  • Read RCHR in US_RHR.
  • If all the data have not been read, redo the two previous steps.
  • Wait until LINTC in US_CSR rises.
  • Check the LIN errors.
• Case 3: NACT = IGNORE, the USART is not concerned by the response
  • Wait until LINTC in US_CSR rises.
  • Check the LIN errors.
    Figure 1. Slave Node Configuration, NACT = PUBLISH

    
    Figure 2. Slave Node Configuration, NACT = SUBSCRIBE

    
    Figure 3. Slave Node Configuration, NACT = IGNORE