Datasheet

807
SAM9G15 [DATASHEET]
11052D–ATARM–31-Oct-12
Figure 39-47.Master Node Configuration, NACT=IGNORE
Slave Node Configuration
z Write TXEN and RXEN in US_CR to enable both the transmitter and the receiver.
z Write USART_MODE in US_MR to select the LIN mode and the Slave Node configuration.
z Write CD and FP in US_BRGR to configure the baud rate.
z Wait until LINID in US_CSR rises
z Check LINISFE and LINPE errors
z Read IDCHR in US_RHR
z 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 register, must be write 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:
z Case 1: NACT = PUBLISH, the LIN controller sends the response
z Wait until TXRDY in US_CSR rises
z Write TCHR in US_THR to send a byte
z If all the data have not been written, redo the two previous steps
z Wait until LINTC in US_CSR rises
z Check the LIN errors
z Case 2: NACT = SUBSCRIBE, the USART receives the response
z Wait until RXRDY in US_CSR rises
z Read RCHR in US_RHR
z If all the data have not been read, redo the two previous steps
z Wait until LINTC in US_CSR rises
z Check the LIN errors
z Case 3: NACT = IGNORE, the USART is not concerned by the response
z Wait until LINTC in US_CSR rises
z Check the LIN errors
TXRDY
Write
US_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