SAA7108AE Datasheet, PDF (29/208 Pages) NXP Semiconductors – HD-CODEC

NXP Semiconductors
SAA7108AE; SAA7109AE
HD-CODEC
To ease the trigger set-up for the sync generation module, a set of registers is provided to
set up the screen raster which is defined as width and height. A trigger position can be
specified as an x, y co-ordinate within the overall dimensions of the screen raster. If the
x, y counter matches the specified co-ordinates, a trigger pulse is generated which
pre-loads the tables with their initial values.
The listing in Table 9 outlines an example on how to set up the sync tables for a 1080i HD
raster.
Important note: Due to a problem in the programming interface, writing to the line pattern
array (address D2) might destroy the data of the line type array (address D1). A work
around is to write the line pattern array data before writing the line type array. Reading of
the arrays is possible but all address pointers must be initialized before the next write
operation.
4-bit line type index
10-bit line count
LINE COUNT ARRAY
16 entries
line
count
pointer
SAA7108AE_SAA7109AE_3
Product data sheet
line type pointer
33333333
LINE TYPE ARRAY
15 entries
33333333
pattern pointer
event type pointer
10-bit duration 10-bit duration 10-bit duration 10-bit duration
4-bit value index 4-bit value index 4-bit value index 4-bit value index
8 + 2-bit value
VALUE ARRAY
8 entries
LINE PATTERN ARRAY
7 entries
line pattern pointer
mbl797
Fig 12. Context between the pattern generator tables for DH sync pulses
Table 9. Example for setup of the sync tables
Sequence (hexadecimal) Comment
Write to subaddress D0h
00
points to first entry of line count array (index 0)
05 20
generate 5 lines of line type index 2 (this is the second entry of the
line type array); will be the first vertical raster pulse
01 40
generate 1 line of line type index 4; will be sync-black-sync-black
sequence after the first vertical pulse
0E 60
generate 14 lines of line type index 6; will be the following lines with
sync-black sequence
Rev. 03 — 6 February 2007
© NXP B.V. 2007. All rights reserved.
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