Atmel Evaluation Kit AT91SAM9X25-EK AT91SAM9X25-EK Scheda Tecnica

Codici prodotto
AT91SAM9X25-EK
Pagina di 1151
830
SAM9X25 [DATASHEET]
11054E–ATARM–10-Mar-2014
Identifier Parity Error
This error is generated in Slave node configuration, if the parity of the identifier is wrong. This error can be generated 
only if the parity feature is enabled (PARDIS = 0).
This error is reported by flag LINIPE in the Channel Status Register (US_CSR).
Checksum Error
This error is generated in Master of Slave node configuration, if the received checksum is wrong. This flag can be set to 
“1” only if the checksum feature is enabled (CHKDIS = 0).
This error is reported by flag LINCE in the Channel Status Register (US_CSR).
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, TFrame_Maximum (see 
). This error is disabled if the USART does not expect any 
message (NACT = PUBLISH or NACT = IGNORE).
This error is reported by flag LINSNRE in the Channel Status Register (US_CSR). 
39.7.8.15 LIN Frame Handling
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