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DMA Registers
5-106
ADSP-BF537 Blackfin Processor Hardware Reference
DMA_TC_CNT Register
The
MDMA_ROUND_ROBIN_COUNT
field shows the current transfer count
remaining in the MDMA round robin period. It initializes to
MDMA_ROUND_
ROBIN_PERIOD
whenever
DMA_TC_PER
is written, whenever a different
MDMA stream is granted, or whenever every MDMA stream is idle. It
then counts down to 0 with each MDMA transfer. When this count dec-
rements from 1 to 0, the next available MDMA stream is selected.
The
DAB_TRAFFIC_COUNT
field shows the current cycle count remaining in
the DAB traffic period. It initializes to
DAB_TRAFFIC_PERIOD
whenever
DMA_TC_PER
is written, or whenever the DAB bus changes direction or
becomes idle. It then counts down from
DAB_TRAFFIC_PERIOD
to 0 on each
system clock (except for DMA stalls). While this count is nonzero, same
direction DAB accesses are treated preferentially. When this count decre-
ments from 1 to 0, the opposite direction DAB access is treated
preferentially, which may result in a direction change. When this count is
0 and a DAB bus access occurs, the count is reloaded from
DAB_TRAFFIC_
PERIOD
to begin a new burst.
Figure 5-27. DMA Traffic Control Counter Register
RO
0
0
0
15 14
13 12
11 10
9
8
7
6
5
4
3
2
1
0
0
0
0
0
0
0
0
0
0
0
0
0
0
Current transfer count remaining in
the MDMA round robin period
DMA Traffic Control Counter Register (DMA_TC_CNT)
DAB_TRAFFIC_COUNT[2:0]
Current cycle count remaining in the
DAB traffic period
MDMA_ROUND_ROBIN_
COUNT[4:0]
DCB_TRAFFIC_COUNT[3:0]
DEB_TRAFFIC_COUNT[3:0]
Reset = 0x0000
Current cycle count remaining
in the DCB traffic period
Current cycle count remaining
in the DEB traffic period
Содержание Blackfin ADSP-BF537
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Страница 90: ...Development Tools 1 32 ADSP BF537 Blackfin Processor Hardware Reference ...
Страница 138: ...Programming Examples 4 26 ADSP BF537 Blackfin Processor Hardware Reference ...
Страница 340: ...SDC Programming Examples 6 84 ADSP BF537 Blackfin Processor Hardware Reference ...
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Страница 660: ...Programming Examples 10 54 ADSP BF537 Blackfin Processor Hardware Reference ...
Страница 720: ...Electrical Specifications 11 60 ADSP BF537 Blackfin Processor Hardware Reference ...
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Страница 986: ...Programming Examples 18 28 ADSP BF537 Blackfin Processor Hardware Reference ...
Страница 1162: ...G 26 ADSP BF537 Blackfin Processor Hardware Reference ...
Страница 1218: ...Index I 56 ADSP BF537 Blackfin Processor Hardware Reference ...