Atmel Evaluation Kit AT91SAM9G25-EK AT91SAM9G25-EK Data Sheet
Product codes
AT91SAM9G25-EK
816
SAM9G25 [DATASHEET]
11032C–ATARM–25-Jan-13
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.
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Wait until LINID in US_CSR rises
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Check LINISFE and LINPE errors
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Read IDCHR in US_RHR
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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.
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:
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Case 1: NACT = PUBLISH, the LIN controller sends the response
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Wait until TXRDY in US_CSR rises
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Write TCHR in US_THR to send a byte
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If all the data have not been written, redo the two previous steps
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Wait until LINTC in US_CSR rises
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Check the LIN errors
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Case 2: NACT = SUBSCRIBE, the USART receives the response
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Wait until RXRDY in US_CSR rises
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Read RCHR in US_RHR
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If all the data have not been read, redo the two previous steps
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Wait until LINTC in US_CSR rises
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Check the LIN errors
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Case 3: NACT = IGNORE, the USART is not concerned by the response
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Wait until LINTC in US_CSR rises
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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