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

- 18 -

1999 Hyundai System IC Division

PRELIMINARY

(11) Operating Clock Divider (Address 28h, default:00h, R/W)

This register generates divided digital clock depending on the settings clk_div [3:0], digital block can

divide MCLK down by 1 through 2048 as shown in Table 1.

clk_div[3:0]

units

clk_div[3:0]

units

0000

no division

0101

MCLK/64

0001

MCLK/2

0111

MCLK/128

0010

MCLK/4

1000

MCLK/256

0011

MCLK/8

1001

MCLK/512

0100

MCLK/16

1010

MCLK/1024

0101

MCLK/32

1011

MCLK/2048

Table 1. Operating Clock Control Register

(12) Reset Level Control Register (Address 30h, default:38h, R/W)

This register controls reference voltage level for start point of data reading. If the register value is

too large or too small, the vertical Fixed Pattern Noise(FPN) can be occurred. To Get rid of FPN,

this register must have a suitable value. Optimum reset revel can be found using Low reference

number registers 57h ~ 58h and High reference number registers 59h ~ 5ah. If there is some large

value in Low reference number registers, the value of Reset Level control register should be

increased. If there is some large value in High reference number registers, the value of register

should be decrease. Optimum reset revel is achieved when value of Low reference level number

registers and value of High reference number registers is minimized.

(13) Color Gain Register

Red Color Gain Register

:

(Address 31h, default:1Eh, R/W)

Green Color Gain Register :

(Address 32h, default:h1Eh, R/W)

Blue Color Gain Register

:

(Address 33h, default:h1Eh, R/W)

These registers are used to amplify the analog pixel output. If the gain register value is decreased,

the amplification is increased. Therefore under the dark light source condition, the pixel output have

to be amplified by decreasing gain value to get good image. There are three Gain registers to control

RGB colors independently. In the case of monochrome image sensor, use only Green Color Gain

Register. Available program range is 0 ~ 63 but too small value can cause FPN. The register value

have to chosen within the range that doesn’ t cause FPN. Recommended range is 20 ~63. These

register can be used for Auto White Balance control and Auto Exposure control.