Philips Semiconductors
Preliminary specification
PAL/NTSC/SECAM video decoder with adaptive PAL/NTSC
comb filter, VBI-data slicer and high performance scaler
SAA7114H
handbook, full pagewidth
ANALOG INPUT
9
gain
AMPLIFIER
ANTI-ALIAS FILTER
ADC
DAC
9
LUMA/CHROMA DECODER
1
0
NO ACTION
VBLK
1
0
HOLDG
1
0
X
1
0
HSY
0
1
>
254
0
1
1
0
1
0
<
<
>
254
4
1
X = 1
X = 0
1
0
>
248
+/− 0
+1/L
+1/F
+1/LLC2 −1/LLC2
−1/LLC2
STOP
GAIN ACCUMULATOR (18 BITS)
[
]
ACTUAL GAIN VALUE 9-BIT (AGV) −3/+6 dB
1
0
X
1
0
HSY
1
0
Y
AGV
UPDATE
FGV
GAIN VALUE 9-BIT
MHB531
X = system variable.
Y = (IAGV − FGVI) > GUDL.
VBLK = vertical blanking pulse.
HSY = horizontal sync pulse.
AGV = actual gain value.
FGV = frozen gain value.
Fig.7 Gain flow chart.
16
2000 Mar 15