Texas Instruments TMS320C6000 Reference Manual page 23

Devices With DMA
Devices With EDMA
Note:
For devices that have EDMA, the DAT module uses the quick DMA feature.
This means that the module doesn't have to internally allocate a DMA chan-
nel. However, you are still required to open the DAT module before use.
On devices such as the '6201 that have the DMA peripheral, only one request
may be active at once since only one DMA channel is used. If you submit two
requests back to back, the first one will be programmed into the DMA hardware
immediately but the second one will have to wait until the first completes. The
APIs will block (spin) if called while a request is still busy by polling the transfer
complete interrupt flag. The completion interrupt is not actually enabled to
eliminate the overhead of taking an interrupt but the interrupt flag is still active.
On devices with EDMA, it is possible to have multiple requests pending be-
cause of hardware request queues. Each call into the DAT_Copy() or
DAT_Fill() functions return a unique transfer ID number. This ID number
is then used by the user to wait for transfer completion. The ID number allows
the library to distinguish between multiple pending transfers. As with the DMA,
transfer completion is determined by monitoring EDMA transfer complete
codes (interrupt flags).
For additional information about the DAT module, refer to Table 3–3 on page
3-3 and Section 4.4 on page 4-11.
CSL API Module Descriptions
DAT
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