ADSP-BF537 Blackfin Processor Hardware Reference
5-25
Direct Memory Access
Then DMA data transfer operation begins, as shown in
.
DMA Refresh
On completion of a work unit, the DMA controller:
• Completes the transfer of all data between memory and the DMA
unit.
• If
SYNC = 1
and
WNR
=
0
(memory read), selects a synchronized
transition. Transfers all data to the peripheral before continuing.
• If enabled by
DI_EN
, signals an interrupt to the core and sets the
DMA_DONE
bit in the channel’s
DMAx_IRQ_STATUS
register.
• If
FLOW = 0
(stop) only:
Stops operation by clearing the
DMA_RUN
bit in
DMAx_IRQ_STATUS
after any data in the channel’s DMA FIFO has been transferred to
the peripheral.
• During the fetch in
FLOW
modes 4, 6, and 7, the DMA controller
sets the
DFETCH
bit in
DMAx_IRQ_STATUS
to 1. At this point, the
DMA operation depends on whether
FLOW
=
4
,
6
, or
7
, as follows:
If
FLOW = 4
(descriptor array):
Loads a new descriptor from memory into DMA registers via the
contents of
DMAx_CURR_DESC_PTR
, while incrementing
DMAx_CURR_
DESC_PTR
. The descriptor size comes from the
NDSIZE
field of the
DMAx_CONFIG
value prior to the beginning of the fetch.
If
FLOW = 6
(descriptor list small):
Copies the 32-bit
DMAx_NEXT_DESC_PTR
into
DMAx_CURR_DESC_PTR
.
Summary of Contents for Blackfin ADSP-BF537
Page 42: ...Contents xlii ADSP BF537 Blackfin Processor Hardware Reference ...
Page 90: ...Development Tools 1 32 ADSP BF537 Blackfin Processor Hardware Reference ...
Page 138: ...Programming Examples 4 26 ADSP BF537 Blackfin Processor Hardware Reference ...
Page 340: ...SDC Programming Examples 6 84 ADSP BF537 Blackfin Processor Hardware Reference ...
Page 606: ...Programming Examples 9 94 ADSP BF537 Blackfin Processor Hardware Reference ...
Page 660: ...Programming Examples 10 54 ADSP BF537 Blackfin Processor Hardware Reference ...
Page 720: ...Electrical Specifications 11 60 ADSP BF537 Blackfin Processor Hardware Reference ...
Page 840: ...Programming Examples 13 42 ADSP BF537 Blackfin Processor Hardware Reference ...
Page 876: ...Programming Examples 14 36 ADSP BF537 Blackfin Processor Hardware Reference ...
Page 938: ...Programming Examples 15 62 ADSP BF537 Blackfin Processor Hardware Reference ...
Page 958: ...Programming Examples 17 12 ADSP BF537 Blackfin Processor Hardware Reference ...
Page 986: ...Programming Examples 18 28 ADSP BF537 Blackfin Processor Hardware Reference ...
Page 1162: ...G 26 ADSP BF537 Blackfin Processor Hardware Reference ...
Page 1218: ...Index I 56 ADSP BF537 Blackfin Processor Hardware Reference ...