HB7121B

Electronics Industries Co., Ltd.

CMOS IMAGE SENSOR

System IC Division

With 8-bit ADC

This document is a general product description and is subject to change without notice. Hyundai Electronics does not assume

any responsibility for use of circuits described. NO patent licenses are implied.

DA21991011R_1.0

- 19 -

1999 Hyundai System IC Division

PRELIMINARY

(14) Pixel Bias Voltage Register (Address 34h, default:02h, R/W)

This register controls pixel reference level by controlling bias current of pixel output sensing load

transistor. It controls pixel output level itself, compare with that revel register adjust A/D Converter

circuit to calibrate reference level for data reading. Available program range is 0 ~ 7. The larger

register value causes the higher bias current and low pixel output reference level. This register is

option for manufacturer. Users may use default setting and don’ t changed value.

(15) Low Reference Number Register(low_ref_no)

High

:

(Address 57h default:00h, Read Only)

Low

:

(Address 58h, default:00h, Read Only)

Low Reference Number Registers indicates number of pixels in frame that have a value less then 5.

A reference level values of each pixel is compare with ‘ 5’ , and accumulated to these registers

during read state. This counter value called low_ref_no, consist of two bytes and it is read only

registers. Real number of pixels that have value less than 5 is the twice of these register value. If

low_ref_no is big value, you must increase data value of Reset Level Control Register. These

registers are updated after every VSYNC signal.

(16) High Reference Number Register (high_ref_no)

High

:

(Address 59h, default:00h, Read Only)

Low

:

(Address 5Ah, default:00h, Read Only)

High Reference Number Registers indicates number of pixels in a frame that have a value great then

123. Reference level values of each pixels is compared with ‘ 123’ , and accumulated to these

registers during read state. This counter value called high_ref_no, consist of two bytes and it is read

only registers. Real number of pixels that have value great than 123 is the twice of these register

value. If high_ref_no is big value, you must decrease data value of Reset Level Control Register.

These registers are also updated after every VSYNC signal.