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Programming Model
20-22
ADSP-BF50x Blackfin Processor Hardware Reference
the timer itself can be configured and enabled for non-PPI use without
affecting PPI operation in this mode. For more information, see the
General-Purpose Timers
chapter.
Programming Model
The following sections describe the PPI programming model.
DMA Operation
The PPI must be used with the processor’s DMA engine. This section dis-
cusses how the two interact. For additional information about the DMA
engine, including explanations of DMA registers and DMA operations,
refer to the
Direct Memory Access
chapter.
The PPI DMA channel can be configured for either transmit or receive
operation, and it has a maximum throughput of (
PPI_CLK
) ×
(16 bits/transfer). In modes where data lengths are greater than eight bits,
only one element can be clocked in per
PPI_CLK
cycle, and this results in
reduced bandwidth (since no packing is possible). The highest throughput
is achieved with 8-bit data and
PACK_EN
= 1 (packing mode enabled). Note
for 16-bit packing mode, there must be an even number of data elements.
Configuring the PPI’s DMA channel is a necessary step toward using the
PPI interface. It is the DMA engine that generates interrupts upon com-
pletion of a row, frame, or partial-frame transfer. It is also the DMA
engine that coordinates the origination or destination point for the data
that is transferred through the PPI.
The processor’s 2D DMA capability allows the processor to be interrupted
at the end of a line or after a frame of video has been transferred, as well as
if a DMA error occurs. In fact, the specification of the
DMA_XCOUNT
and
DMA_YCOUNT
MMRs allows for flexible data interrupt points. For example,
assume the DMA registers
XMODIFY
=
YMODIFY
= 1. Then, if a data frame
Содержание EZ-KIT Lite ADSP-BF506F
Страница 50: ...Contents l ADSP BF50x Blackfin Processor Hardware Reference ...
Страница 92: ...Development Tools 1 30 ADSP BF50x Blackfin Processor Hardware Reference ...
Страница 110: ...Interface Overview 3 12 ADSP BF50x Blackfin Processor Hardware Reference ...
Страница 132: ...Unique Information for the ADSP BF50x Processor 4 22 ADSP BF50x Blackfin Processor Hardware Reference ...
Страница 236: ...Internal Flash Memory Control Registers 6 92 ADSP BF50x Blackfin Processor Hardware Reference ...
Страница 342: ...Unique Information for the ADSP BF50x Processor 7 106 ADSP BF50x Blackfin Processor Hardware Reference ...
Страница 484: ...Unique Information for the ADSP BF50x Processor 10 60 ADSP BF50x Blackfin Processor Hardware Reference ...
Страница 493: ...ADSP BF50x Blackfin Processor Hardware Reference 11 9 Core Timer Unique Information for the ADSP BF50x Processor None ...
Страница 494: ...Unique Information for the ADSP BF50x Processor 11 10 ADSP BF50x Blackfin Processor Hardware Reference ...
Страница 506: ...Unique Information for the ADSP BF50x Processor 12 12 ADSP BF50x Blackfin Processor Hardware Reference ...
Страница 544: ...Unique Information for the ADSP BF50x Processor 13 38 ADSP BF50x Blackfin Processor Hardware Reference ...
Страница 650: ...Programming Examples 15 56 ADSP BF50x Blackfin Processor Hardware Reference ...
Страница 712: ...Unique Information for the ADSP BF50x Processor 16 62 ADSP BF50x Blackfin Processor Hardware Reference ...
Страница 804: ...Programming Examples 17 92 ADSP BF50x Blackfin Processor Hardware Reference ...
Страница 972: ...Unique Information for the ADSP BF50x Processor 20 38 ADSP BF50x Blackfin Processor Hardware Reference ...
Страница 1194: ...Programming Examples 24 90 ADSP BF50x Blackfin Processor Hardware Reference ...
Страница 1256: ...ACM Registers A 50 ADSP BF50x Blackfin Processor Hardware Reference ...
Страница 1264: ...Boundary Scan Architecture B 8 ADSP BF50x Blackfin Processor Hardware Reference ...