Philips Semiconductors
CS-PD Hamburg
CVIP2
Datasheet
SAA7115
Date:
Version:
10/23/01
0.67
8.1.2.3 Brightness Contrast Saturation (BCS) control and decoder output levels
The resulting Y (CVBS) and CB-CR 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-CB-CR or CVBS to the values 1 (minimum) and 254 (maximum) to fulfil “ITU Recommendation 601/656”.
handbook, full pagewi+d2th55
+235
white
+255
+240
+212
blue 100%
blue 75%
+255
+240
+212
red 100%
red 75%
+128 LUMINANCE 100%
+16
black
0
+128
colourless
CB- COMPONENT
+128
colourless
CR- COMPONENT
+44
yellow 75%
+44
+16
yellow 100%
+16
0
0
cyan 75%
cyan 100%
MHB730
a. Y output range.
b. CB output range.
c. CR output range.
“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-CB-CR levels via BCS control I2C-bus bytes DBRI, DCON and DSAT.
Luminance: YOUT = Int D-----C-6---O8-----N--- × (Y – 128) + DBRI
Chrominance: (CRCB)OUT = Int D-----S6---4-A----T-- × (CR, CB – 128) + 128
It should be noted that the resulting levels are limited to 1 to 254 in accordance with “ITU Recommendation 601/656”.
Fig.18 Y-CB-CR range for scaler input and X-port output.
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Filename: SAA7115_Datasheet.fm
page 38
Last edited by H. Lambers