msm7652 Oki Semiconductor, msm7652 Datasheet - Page 10

• Manufacturer Part Number: msm7652
• Description: Ntsc/pal Digital Video Encoder
• Manufacturer: Oki Semiconductor

MSM7652
BLOCK FUNCTIONAL DESCRIPTION
1. Prologue Block
2. Y Limiter Block
This block limits the luminance input signal by clipping the lower limit of an input signal outside
the ITU601 Standard
• Signals are limited to YD = 16 when YD < 16.
• Signals are limited to TD = 254 when YD (input during a valid pixel period) = 255.
In other cases, signals are fed as is to next processing.
3. C Limiter Block
This block limits the chrominance signal by clipping the upper and lower limits of the input
signal outside the ITU601 Standard.
CD = 1 when CD = 0 is input during a valid pixel period.
CD = 254 when CD = 255 is input during a valid pixel period.
• Y Level Converter
• U Level Converter
• V Level Converter
• YUV Color Generator
• Overlay Control
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This block separates input data at the ITU Rec.656 format into a luminance signal (Y) and a
chrominance signal (Cb & Cr), and also generates information concerning sync signals
HSYNC_L, VSYNC_L, and BLANK_L.
This block separates input data at the 27 MHz YCbCr (8-bit input) format into a luminance
signal (Y) and a chrominance signal (Cb & Cr).
This block separates input data at the 13.5 MHz YCbCr (16-bit input) format into a chrominance
signal Cb and a chrominance signal Cr.
Of the processed input data, luminance and chrominance signals other than valid pixel data
are replaced by 8'h10 and 8'h80 respectively.
Converts ITU-601 standard luminance signal level to DAC digital input level.
Converts ITU-601 standard chrominance signal level to DAC digital input level.
Converts ITU-601 standard chrominance signal level to DAC digital input level.
This block generates luminance and chrominance signals from over lay color signals OLR,
OLG and OLB. Control signals (CR [2:0] ) control the output content (overlay or color bar) and
output level (100%, 75%, 50%, 25%).
This block selects input image data or YUV Color Generator output signals.
It is determined by the level of the control signal (OLC, CR [2]), as shown below: (x : don't care)
CR [2] = 1, OLC = x: Selects color bar signal (YUV Color Generator output signal).
CR [2] = 0, OLC = 1: Selects overlay signal (YUV Color Generator output signal).
CR [2] = 0, OLC = 0: Selects input image data.
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