vpx3224d ETC-unknow, vpx3224d Datasheet - Page 29

• Manufacturer Part Number: vpx3224d
• Description: Video Pixel Decoders
• Manufacturer: ETC-unknow

Micronas
PRELIMINARY DATA SHEET
Fig. 2–33: Mapping for 525/60 line systems
There are some restrictions in the horizontal window
definition. The total number of active pixels (NPix) must
be an even number. The maximum value for NPix should
be 800. Values up to 864 are possible, but for short input
lines, video data is not guaranteed at the end of the line
since VACT will be interrupted at the beginning of the
next line. HLength should also be an even number. Ob-
viously, the sum of HBegin and HLength may not be
greater than NPix.
Window boundaries are defined by writing the dimen-
sions into the associated WinLoadTab and then setting
the corresponding latch bit in the control word FP-RAM
0x140 [latwin]. Window definition data is latched at the
beginning of the next video frame. Once the WinLoad-
Tab data has been latched, the latch bit in the Control
word is reset. By polling the Infoword (FP-RAM 0x141),
the external controller can know when the window
boundary data has been read. Window definition data
can be changed only once per frame. Multiple window
definitions within a single frame time are ignored and
can lead to error.
260
261
262
263
264
265
266
18
19
20
21
4
5
6
7
Field 1
D
D
D
D
D
D
260
261
262
263
264
265
266
18
19
20
21
4
5
6
7
267
268
269
270
281
282
283
284
523
524
525
1
2
3
Field 2
D
D
D
D
D
D
260
261
262
263
264
265
18
19
20
21
4
5
6
7
Fig. 2–34: Mapping for 625/50 line systems
2.11. Temporal Decimation
To cope with bandwidth restrictions in a system, the VPX
supports temporal dropping of video frames via sup-
pression of the VACT signal. Dropping will be applied for
video windows only. There is no influence on the state
of the VBI-window. This mode can be activated for each
video window by setting the enable flag in the corre-
sponding WinLoadTab (FP-RAM 0x121/12B). The
selection in FP-RAM 0x157 determines how many
frames will be output within an interval of 3000 frames.
Note that this selection is applied for both video win-
dows, but decimation can be enabled for each window
separately. The number of valid frames is updated only
if the corresponding latch flag in FP-RAM 0x140 [lattdec]
is set. Frame dropping with temporal decimation can be
combined with the field disable flags (FP-RAM
0x121/12B). Within valid video frames, each field type
can be disabled separately.
308
309
310
312
313
311
22
23
24
25
1
2
3
4
VPX 3225D, VPX 3224D
Field 1
D
D
D
D
D
D
308
309
310
312
313
311
22
23
24
25
1
2
3
4
335
336
337
338
621
622
623
624
625
315
316
317
314
Field 2
D
D
D
D
D
D
308
309
310
312
311
22
23
24
25
1
2
3
4
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