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SCI

28.2.3 SCI DMA Interface

DMA requests for receive (RXDMA request) and transmit (TXDMA request) are available for the SCI/LIN

module. The DMA transfers depending on whether multi-buffer mode bit (MBUF MODE) is enabled or not.

For DMA module configuration refer

28.2.3.1 Receive DMA Requests

This DMA functionality is enabled/disabled by the CPU using the SET RX DMA/CLR RX DMA bits,

respectively.

In Multi Buffered SCI mode with DMA enabled, the receiver loads the RDy buffers for each received

character. RX DMA request is triggered once the last character of the programmed number of characters

(LENGTH) are received and copied to the corresponding RDy buffer sucessfully.

If the multi-buffer option is disabled, then DMA requests will be generated on a byte-per-byte basis until all

the expected response data fields are received.

In multiprocessor mode, the SCI can generate receiver interrupts for address frames and DMA requests

for data frames or DMA requests for both. This is controlled by the SET RX DMA ALL bit.

In multiprocessor mode with the SLEEP bit set, no DMA is generated for received data frames. The

software must clear the SLEEP bit before data frames can be received.

28.2.3.2 Transmit DMA Requests

DMA functionality is enabled/disabled by the CPU with SET TX DMA/CLR TX DMA bits, respectively.

In Multi Buffered SCI mode once TXRDY bit is set or after a transmission of programmed number of

characters (LENGTH) (up to eight data bytes stored in the transmit buffer(s) TDy in the LINTD0 and

LINTD1 registers), a DMA request is generated in order to reload the transmit buffer for the next

transmission. If the multi-buffer option is disabled, then DMA requests will be generated on a byte-per-byte

basis until all bytes are transferred.

1359

SPNU562–May 2014 Serial Communication Interface (SCI)/Local Interconnect Network (LIN)

Module

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