Datasheet

46.6.9.14.5 Slave Not Responding Error
This error is generated in master of slave node configuration, when the USART expects a response from another
node (NACT = SUBSCRIBE) but no valid message appears on the bus within the time given by the maximum length
of the message frame, t
Frame_Maximum
(see Frame Slot Mode). This error is disabled if the USAR
T does not expect
any message (NACT = PUBLISH or NACT = IGNORE).
This error is reported by flag US_CSR.LINSNRE.
46.6.9.14.6 Synch Tolerance Error
This error is generated in slave node configuration if, after the clock synchronization procedure, it appears that the
computed baudrate deviation compared to the initial baudrate is superior to the maximum tolerance FTol_Unsynch
(±15%).
This error is reported by flag US_CSR.LINSTE.
46.6.9.14.7 Header Timeout Error
This error is generated in slave node configuration, if the Header is not entirely received within the time given by the
maximum length of the Header
, t
Header_Maximum
.
This error is reported by flag US_CSR.LINHTE.
46.6.9.15 LIN Frame Handling
46.6.9.15.1 Master 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 master node configuration.
• Write CD and FP in US_BRGR to configure the baud rate.
• Write NACT, PARDIS, CHKDIS, CHKTYPE, DLCM, FSDIS and DLC in US_LINMR to configure the frame
transfer.
• Check that TXRDY in US_CSR is set to 1.
• Write IDCHR in US_LINIR to send the header.
What comes next depends on the NACT configuration:
• Case 1: NACT = PUBLISH, the USART 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.
SAM E70/S70/V70/V71 Family
Universal Synchronous Asynchronous Receiver T
ransc...
© 2019 Microchip T
echnology Inc.
Datasheet
DS60001527D-page 1214