Philips Semiconductors
Product specification
Multimedia bridge, high performance
Scaler and PCI circuit (SPCI)
SAA7146A
Table 85 Chrominance saturation control
D7
D6
D5
D4
D3
D2
D1
D0
GAIN
0
0
0
1
1
0
1
0
0
1
0
0
1
0
0
1
0
0
1
0
0
1
0
0
1.999 (max. saturation)
1 (CCIR level)
0 (colour off)
7.12.8 CHROMA KEY
Table 86 Chroma key range
OFFSET
(HEX)
NAME
BIT
TYPE
DESCRIPTION
74
VL
31 to 24
23 to 16
15 to 8
7 to 0
RW
set lower limit V for chroma keying (8-bit; twos complement):
1000 0000: as maximum negative value = −128 signal level
0000 0000: limit = 0
0111 1111: as maximum positive value = +127 signal level
set upper limit V for chroma keying (8-bit; twos complement):
1000 0000: as maximum negative value = −128 signal level
0000 0000: limit = 0
VU
UL
UU
RW
RW
RW
0111 1111: as maximum positive value = +127 signal level
set lower limit U for chroma keying (8-bit; twos complement):
1000 0000: as maximum negative value = −128 signal level
0000 0000: limit = 0
0111 1111: as maximum positive value = +127 signal level
set upper limit U for chroma-keying (8-bit; twos complement):
1000 0000: as maximum negative value = −128 signal level
0000 0000: limit = 0
0111 1111: as maximum positive value = +127 signal level
1998 Apr 09
95
NXP [ NXP ]
