DMA Registers
7-72
ADSP-BF50x Blackfin Processor Hardware Reference
DMA Interrupt Status Registers
(DMAx_IRQ_STATUS/MDMA_yy_IRQ_STATUS)
The DMAx_IRQ_STATUS register, shown in
Figure 7-7
, contains bits
that record whether the DMA channel:
• Is enabled and operating, enabled but stopped, or disabled.
• Is fetching data or a DMA descriptor.
• Has detected that a global DMA interrupt or a channel interrupt is
being asserted.
• Has logged occurrence of a DMA error.
Note the
DMA_DONE
interrupt is asserted when the last memory access (read
or write) has completed.
For a memory transfer to a peripheral, there may be up to four data
words in the channel’s DMA FIFO when the interrupt occurs. At
this point, it is normal to immediately start the next work unit. If,
however, the application needs to know when the final data item is
actually transferred to the peripheral, the application can test or
poll the
DMA_RUN
bit. As long as there is undelivered transmit data
in the FIFO, the
DMA_RUN
bit is 1.
For a memory write DMA channel, the state of the
DMA_RUN
bit has
no meaning after the last
DMA_DONE
event has been signaled. It does
not indicate the status of the DMA FIFO.
For MDMA transfers where an interrupt is not desired to notify
when the DMA operation has ended, software should poll the
DMA_DONE
bit, rather than the
DMA_RUN
bit to determine when the
transaction has completed.
Summary of Contents for EZ-KIT Lite ADSP-BF506F
Page 50: ...Contents l ADSP BF50x Blackfin Processor Hardware Reference ...
Page 92: ...Development Tools 1 30 ADSP BF50x Blackfin Processor Hardware Reference ...
Page 110: ...Interface Overview 3 12 ADSP BF50x Blackfin Processor Hardware Reference ...
Page 236: ...Internal Flash Memory Control Registers 6 92 ADSP BF50x Blackfin Processor Hardware Reference ...
Page 650: ...Programming Examples 15 56 ADSP BF50x Blackfin Processor Hardware Reference ...
Page 804: ...Programming Examples 17 92 ADSP BF50x Blackfin Processor Hardware Reference ...
Page 1194: ...Programming Examples 24 90 ADSP BF50x Blackfin Processor Hardware Reference ...
Page 1256: ...ACM Registers A 50 ADSP BF50x Blackfin Processor Hardware Reference ...
Page 1264: ...Boundary Scan Architecture B 8 ADSP BF50x Blackfin Processor Hardware Reference ...