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NXP Semiconductors
PNX15xx/952x Series
Volume 1 of 1
Chapter 12: Video Input Processor
PNX15XX_PNX952X_SER_N_4
NXP B.V. 2007. All rights reserved.
Product data sheet
Rev. 4.0 — 03 December 2007
12-443
Auxiliary Data Acquisition
Capturing auxiliary data utilizes the same DMA engine used for the third video plane.
Capture of overlapping Video and Auxiliary regions is, therefore, only possible when
semi-planar or packed formats are being used. Data can be captured in either 8- or
10-bit modes. In the single-stream mode, 10-bit data is extended to 16 bits by either
adding leading zeros or by sign-extension. In dual stream mode, only 8 MSBs of a 10-
bit data are valid; two such MSB sets (2x8-bit data) are captured simultaneously, for
either 8-bit or 10-bit modes, and packed to form a resultant 16-bit unit. thus, Channel
A data (8 bits) and channel B data (8 bits) are located at the 8 LSBs and the 8 MSBs
respectively, of the packed 16-bit data.
Three different types of auxiliary data capture are dened:
Ancillary Data Capture (ANC)
Auxiliary data acquisition window (AUX)
Raw data capture (RAW)
A buffer-size register can be used to limit data acquisition by size (one shot mode) or
dene a ring-buffer length.
Even though ANC and AUX capture can be enabled separately, simultaneous capture
of ANC and AUX is not advisable. Timing and sequence of ANC and AUX data are
not necessarily related and therefore are likely to lead to unpredictable results if
simultaneous capture is attempted!
Ancillary Data Capture
Ancillary Data, embedded in the stream and marked by ITU-R-1364 header codes,
can be decoded and extracted for software processing (see
Figure 13). AUX_BPS
register species the number of bits to be captured per ANC sample. In the 8-bit
mode, two LSBs of the 10-bit data bus are ignored. Ancillary data capture is not
supported in the dual stream mode.
Figure 13: ANC Data Structure
DBN*
00
+
FF
+
FF
+
DID
DC
CS
data
ANC
preamble
user data words
(max.255)
+8 MSB of input data checked
DBN*
DC
CS
size of 8-bit user data words = DC[7:2] x 4
size of 10-bit user data words = DC[7:0]
ancillary data packet:
captured data:
data bit allocation:
3
4
1
2
0
8
9
6
7
5
8-bit data range
10-bit data range
MSB
LSB
DID
*DBN for type 1 or SDID for type 2 (ITU-R-1364)