Quatech MPA-200/300, RS-422/485 D1 -RXSRC, Receive DMA Source, D0 -TXSRC, Transmit DMA Source

Models: RS-422/485 MPA-200/300

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D1 -RXSRC, RECEIVE DMA SOURCE:

When set (logic 1), this bit allows the source for receive DMA to come from the W/REQB pin of channel B on the SCC. When cleared (logic 0), the source for receive DMA comes from the W/REQA pin of channel A on the SCC.

D0 -TXSRC, TRANSMIT DMA SOURCE:

When set (logic 1), this bit allows the source for transmit DMA to come from the DTR/REQA pin of channel A on the SCC. When cleared (logic 0), the source for transmit DMA comes from the W/REQA pin of channel A on the SCC.

NOTE:

If both D0 and D1 are cleared (logic 0), then the transmit and receive DMA requests both come from the W/REQA pin of channel A on the SCC. Proper board function is not guaranteed under this condition.

Quatech Inc., MPA-200/300 Manual

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Quatech MPA-200/300, RS-422/485 user manual D1 -RXSRC, Receive DMA Source, D0 -TXSRC, Transmit DMA Source