ADSP-BF537 Blackfin Processor Hardware Reference
5-107
Direct Memory Access
The
DEB_TRAFFIC_COUNT
field shows the current cycle count remaining in
the DEB traffic period. It initializes to
DEB_TRAFFIC_PERIOD
whenever
DMA_TC_PER
is written, or whenever the DEB bus changes direction or
becomes idle. It then counts down from
DEB_TRAFFIC_PERIOD
to 0 on each
system clock (except for DMA stalls). While this count is nonzero, same
direction DEB accesses are treated preferentially. When this count decre-
ments from 1 to 0, the opposite direction DEB access is treated
preferentially, which may result in a direction change. When this count is
0 and a DEB bus access occurs, the count is reloaded from
DEB_TRAFFIC_
PERIOD
to begin a new burst.
The
DCB_TRAFFIC_COUNT
field shows the current cycle count remaining in
the DCB traffic period. It initializes to
DCB_TRAFFIC_PERIOD
whenever
DMA_TC_PER
is written, or whenever the DCB bus changes direction or
becomes idle. It then counts down from
DCB_TRAFFIC_PERIOD
to 0 on each
system clock (except for DMA stalls). While this count is nonzero, same
direction DCB accesses are treated preferentially. When this count decre-
ments from 1 to 0, the opposite direction DCB access is treated
preferentially, which may result in a direction change. When this count is
0 and a DCB bus access occurs, the count is reloaded from
DCB_TRAFFIC_
PERIOD
to begin a new burst.
Programming Examples
The following examples illustrate memory DMA and handshaked memory
DMA basics. Examples for peripheral DMAs can be found in the respec-
tive peripheral chapters.
Register-Based 2D Memory DMA
shows a register-based, two-dimensional MDMA. While the
source channel processes linearly, the destination channel resorts elements
by mirroring the two-dimensional data array. See
.
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 ...