PixArt Imaging Inc.
PAS005B
CMOS Image Sensor IC
EXAMPLE_2: VGA Exposure time setting
when system clock 48M hz
pxclk
16M hz
4/120 sec
exposure time
Please keep L_P_F = 483
and Calculate Ny = ? and Ne = ? ,
Application
System_clk
48
Np
3
Pixel_clk
16
Power frequency EX_time (x/120)
60HZ
4
C_nov
0
L_P_F
frame_rate<30
28.98046717
3
483
Register setting
CM
1
row_average
CDSx2
single_path
1
1
1
Wcw
1287
Wrd
967
Cf
1
rf
1
Key in Register
L_P_F
Ny
16
Ne
332
t_line
1136
483
1.ExposureTim ={[(LPF+1+2)-Ny]*t_line- Ne}/Pxclk
2. t_line = (active_line_pixel + t_nov + 12) = 644 + 480 + 12 = 1136 Pxclk
t_nov = 480 + Cov Pxclk
3. Ny = INT[(L_P_F+3) - (( EX_Time * Pxclk ) / t_line)]
16 = INT [(483+3 ) - (( 4 /120
* 16 M ) / 1136 )]
4.Ne = Res[(L_P_F + 3) - (( EX_Time * Pixel_clk ) / t_line)] * active_line_pixel
332 = Res[( 483 + 3 ) - (( 4/120
* 16 M
) / 1136 )] * 644
1
5. Frame rate =
= 1/(483+3)* 1136 = 29
(LPF +1+ 2)⋅t _ line
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PixArt Imaging Inc.
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PIXART [ PIXART IMAGING INC. ]
