Datasheet

616
32117D–AVR-01/12
AT32UC3C
Figure 25-47. Master Node Configuration, NACT=IGNORE
25.6.11.2 Slave Node Configuration
• Write TXEN and RXEN in CR to enable both the transmitter and the receiver.
• Write MODE in MR to select the LIN mode and the Slave Node configuration.
• Write CD and FP in BRGR to configure the baud rate.
• Wait until LINID in CSR rises
• Check LINISFE and LINPE errors
• Read IDCHR in RHR
• Write NACT, PARDIS, CHKDIS, CHKTYPE, DLCM and DLC in LINMR to configure the frame
transfer.
IMPORTANT: if the NACT configuration for this frame is PUBLISH, the US_LINMR register,
must be write with NACT=PUBLISH even if this field is already correctly configured, that in order
to set the TXREADY flag and the corresponding Peripheral DMA Controller write transfer
request.
What comes next depends on the NACT configuration:
• Case 1: NACT = PUBLISH, the USART sends the response
– Wait until TXRDY in CSR rises
– Write TCHR in THR to send a byte
– If all the data have not been written, redo the two previous steps
– Wait until LINTC in CSR rises
– Check the LIN errors
• Case 2: NACT = SUBSCRIBE, the USART receives the response
– Wait until RXRDY in CSR rises
– Read RCHR in RHR
– If all the data have not been read, redo the two previous steps
– Wait until LINTC in CSR rises
– Check the LIN errors
TXRDY
Write
LINIR
RXRDY
LINTC
Break
Synch
Protected
Identifier
Data 1
Data N
Checksum
Data N-1
Header
Inter-
frame
space
Response
space
Frame
Frame slot = TFrame_Maximum
Response
Data3
FSDIS=1 FSDIS=0