Rainbow Electronics AT91CAP9S250A User Manual

Page 284

Advertising
background image

284

6264A–CAP–21-May-07

AT91CAP9S500A/AT91CAP9S250A

26.3.3.3

Single Transactions

Writing a 1 to the DMAC_SREQ[2x] register starts a source single transaction request, where x
is the channel number. Writing a 1 to the DMAC_SREQ[2x+1] register starts a destination single
transfer request, where x is the channel number.

Upon completion of the chunk transaction, the hardware clears the DMAC_SREQ[x] or
DMAC_SREQ[2x+1].

Software can poll the relevant channel bit in the DMAC_CREQ[2x]/DMAC_CREQ[2x+1] and
DMAC_SREQ[x]/DMAC_SREQ[2x+1] registers. When both are 0, then either the requested
chunk or single transaction has completed.

Advertising