ADSP-BF50x Blackfin Processor Hardware Reference
20-33
Parallel Peripheral Interface
Take care to ensure that the number of samples programmed into
PPI_COUNT
is in keeping with the number of samples expected dur-
ing the “horizontal” interval specified by
PPI_FS1
.
PPI Lines Per Frame Register (PPI_FRAME)
The
PPI_FRAME
register, shown in
Figure 20-17
, is used in all TX and RX
modes with two or three frame syncs. For ITU-R 656 modes, this register
holds the number of lines expected per frame of data, where a frame is
defined as field 1 and field 2 combined, designated by the
F
indicator in
the ITU-R stream. Here, a line is defined as a complete ITU-R 656
SAV-EAV cycle.
For non ITU-R 656 modes with external frame syncs, a frame is defined as
the data bounded between
PPI_FS2
assertions, regardless of the state of
PPI_FS3
. A line is defined as a complete
PPI_FS1
cycle. In these modes,
PPI_FS3
is used only to determine the original “frame start” each time the
PPI is enabled. It is ignored on every subsequent field and frame, and its
state (high or low) is not important except during the original frame start.
If the start of a new frame (or field, for ITU-R 656 mode) is detected
before the number of lines specified by
PPI_FRAME
have been transferred, a
frame track error results, and the
FT_ERR
bit in
PPI_STATUS
is set.
Figure 20-16. PPI Transfer Count Register
PPI Transfer Count Register (PPI_COUNT)
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
0
0
0
PPI_COUNT[15:0]
Reset = 0x0000
In RX modes, holds one less
than the number of samples to
read in to the PPI per line. In
TX modes, holds one less
than the number of samples to
write out through the PPI per
line.
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 ...