SAA7108AE Datasheet, PDF (54/208 Pages) NXP Semiconductors – HD-CODEC

NXP Semiconductors
SAA7108AE; SAA7109AE
HD-CODEC
9.1.3.3 Brightness Contrast Saturation (BCS) control and decoder output levels
The resulting Y (CVBS) and C_B-C_R signals are fed to the BCS block, which contains the
following functions:
• Chrominance saturation control by DSAT7 to DSAT0
• Luminance contrast and brightness control by DCON7 to DCON0 and
DBRI7 to DBRI0
• Raw data (CVBS) gain and offset adjustment by RAWG7 to RAWG0 and
RAWO7 to RAWO0
• Limiting Y-C_B-C_R or CVBS to the values 1 (minimum) and 254 (maximum) to fulfil
‘ITU Recommendation 601/656’
+255
+235
white
+255
+240
+212
blue 100 %
blue 75 %
+255
+240
+212
red 100 %
red 75 %
+128 LUMINANCE 100 %
+128
colorless
C_B-COMPONENT
+128
colorless
C_R-COMPONENT
+44
+16
black
+16
0
0
001aac241
yellow 75 %
+44
yellow 100 %
+16
0
001aac480
cyan 75 %
cyan 100 %
001aac481
‘ITU Recommendation 601/656’ digital levels with default BCS (decoder) settings DCON[7:0] = 44h, DBRI[7:0] = 80h and
DSAT[7:0] = 40h.
Equations for modification to the Y-C_B-C_R levels via BCS control I²C-bus bytes DBRI, DCON and DSAT.
Luminance: Y _OUT
= Int
-^D----^C-----^O----^N---
68
×
(Y
–
128
)
+ DBRI
Chrominance: (C_RC_B)_OUT = Int -^D----^S6---₄-^A----^T-- × (C_R,C_B – 128) + 128
It should be noted that the resulting levels are limited to 1 to 254 in accordance with ‘ITU Recommendation 601/656’
a. Y output range.
b. C_B output range.
c. C_R output range.
Fig 27. Y-C_B-C_R range for scaler input and X port output
SAA7108AE_SAA7109AE_3
Product data sheet
Rev. 03 — 6 February 2007
© NXP B.V. 2007. All rights reserved.
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