PAS6311LT Specification

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PixArt Imaging Inc.

v1.5 2007/10/02

3.8. Sub-Sampling

PAS6311LT can be programmed to output image in QVGA and QQVGA size. For QVGA sub-sampling

mode, both vertical and horizontal pixels are divided by 2; For QQVGA sub-sampling mode, both vertical

and horizontal pixels are divided by 4. By programming Skip_Analog and Skip_Digital, the maximum

sub-sampling rate is 1/64 ( Skip_Analog + Skip_Digital ).

3.8.1. Skip_Analog

Analog sub-sampling to (1/2) * VGA size readout :

H_Start[9:0] = 0,

V_Start[8:0] = 0,

H_Size[9:0] = 647,

V_Size[8:0]= 487,

Nov_Size[7:0] = 136,

Skip_Analog = 1 ( sub-sampling 1/2 )

Figure 3.6

Valid pixels = ( H_Size + 1 ) / Skip_Analog = ( 647 + 1 ) / 2 = 324

Valid lines = ( V_Siez + 1 ) / Skip_Analog = ( 487 + 1 ) / 2 = 244

Figure 3.7 Inter-line timing of Skip_Analog = 1