PAS302BCW-22S
CMOS Image Sensor IC
3. Function Description
3.1Defect Compensation
The Defect Compensation block can detect the possible defect pixel and replace it with average
output of like-colored pixels from near side of defect pixel. There is no limitation capability of
defect pixel number. This function can be programmed to enable/disable by user.
3.2Companding Curves
The companding function which means compressing and expanding is used to simulate the
gamma curve and do non-linear transformation before the data is output. There are 4 curves
selected by setting Register Compand_Sel as shown in Fig. 3.1. This function can be
programmed to enable/disable by user.
O/P ( 10-Bit)
11,1111,1111
3
2
1
0
without companding
00,0xxx,xxxx 00,1xxx,xxxx
010
011
10,xxxx,xxxx
11,xxxx,xxxx
I/P ( 10-Bit)
Figure 3.1 Companding curves programmed by Compand_EnH and Compand_Sel.
3.3 Power Down Mode
The PAS302BCW-22S can be powered down by setting register “Sw_PwrDn” = 1 or by enable
Pwdn pin. The register value will sustain in the power down mode. PAS302BCW-22S supports 2
power down modes:
z
Software power down：Set register “Sw_PwrDn” = 1 to power down all the internal block
except I2CTM
.
z
Hardware power down：Pull Pwdn pin to high to power down the chip. The chip will go into
standby mode.
3.4Reset Mode
The PAS302BCW-22S can be reseted by setting register “Sw_Reset” = 1 or by enable Reset
pin. PAS302BCW-22S supports 2 reset modes:
z
z
Software reset：Set register “Sw_Reset” = 1 to reset all the I2CTM registers.
Hardware reset：Pull Reset pin to high to reset the full chip.
Version 2.4, 20 Sep. 2005
PixArt Imaging Inc.
4
E-mail: fae_service@pixart.com.tw
PIXART [ PIXART IMAGING INC. ]
