Xilinx LogiCORE IP, User Manual

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66 www.xilinx.com Video Scaler v4.0 User Guide
UG805 March 1, 2011
Chapter 9: Performance
Example 5: Down-scaling 800x600 60Hz YC4:2:2 to 640x480
Assuming 30 kHz line rate
Vertical scale ratio = 0.8
Horizontal scale ratio = 0.8
FLineIn = 30000
Single-engine implementation
CyclesRequiredPerOutputLine = 2*800 + 150 (approximately)
MaxVHoldsPerInputAperture = round_up(480/600) = 1
MaxClksTakenPerVAperture = 1750 * 1= 1750
MinF'clk' = 30000*1750 = 52.5 MHz
Shrink-factor inputs:
hsf=2
20
x (1/0.8) = 0x140000
vsf=2
20
x (1/0.8) = 0x140000
This conversion will work in any of the supported devices and speed grades.
Example 6: Down-scaling 1080P60 YC4:2:2 to 720P/60
67.5 kHz line rate
Vertical scale ratio = 0.6667
Horizontal scale ratio = 0.6667
FLineIn = 67500
Single-engine implementation
CyclesPerOutputLine = 2*1920 + 3*50 (approximately)
MaxVHoldsPerInputAperture = round_up(720/1080) = 1
MaxClksTakenPerVAperture = 3990 * 1 = 3990
MinF'clk' = 67500*3990 = 269.32 MHz
Shrink-factor inputs:
hsf=220 x (1/0.6667) = 0x180000
vsf=220 x (1/0.6667) = 0x180000
When using a single-engine, this conversion will not work with or without frame
buffers (see below - Memory mode) unless using higher speed-grade Virtex-5 or
Virtex-6 devices.
Example 7: Down-scaling 1080P60 YC4:2:2 to 720P/60
67.5 kHz line rate
Vertical scale ratio = 0.6667
Horizontal scale ratio = 0.6667
FLineIn = 67500
Dual-engine implementation
CyclesPerOutputLine = 1*1920 + 2*50 (approximately)
MaxVHoldsPerInputAperture = round_up(720/1080) = 1
MaxClksTakenPerVAperture = 2020 * 1 = 3990
MinF'clk' = 67500*2020 = 136.35 MHz
Shrink-factor inputs:
hsf=220 x (1/0.6667) = 0x180000
vsf=220 x (1/0.6667) = 0x180000
This conversion will work in any of the supported devices and speed grades.