Revision 1.3

Mar.22 2001

-12-

GL646USB

6. Application Description

6.1. System Clock

Internal PLL or external clock input.

A. PLL: 12MHz input , 24 or 32 MHz output to internal system and 48MHz output to internal USB controller.

B. USB2.0 supply: External USB2.0 controller support 24,30,48 MHz to three in one ASIC.

C. Crystal supply: depend on crystal input (receptible frequency of ASIC: 12 to 48 MHz)

6.2. Pixel Clock

A. Normal Mode(three line in):

a. 24 system clock/pixel

b. Chunky color scan(three line in) or fine gray scan for CCD.

B. Fast Mode(one line in) :

a. 9,12 or 15 system clock/pixel three type.

b. Planar color scan (one line in) or Monochrome scan.

c. Fast gray or black & white scan for CCD.

d. Planar color(one line in) for CCD line by turns or line by line.

e. Planar color(one line in),gray, true gray or black & white scan for CIS.

Note : Chunky Color is R1G1B1,R2G2B2,R3G3B3,………

Planar Color is R1,R2,R3,…..;G1,G2,G3,…….;B1,B2,B3,……..

CCD : Chunky color or planar color.

CIS : Planar color

6.3. Scan Speed

A. System clock = 24 MHz :

a. Normal Mode: Chunky color or fine gray scan.

24x41.666ns/pixel = 1.0us/pixel

(1). 600dpi : 5.4ms/line

(2). 1200dpi : 10.4ms/line

b. Fast Mode: Planar color, fast gray or black&white scan.

9x41.666ns/pixel = 0.375us/pixel

12x41.666ns/pixel = 0.5us/pixel

15x41.666ns/pixel = 0.625us/pixel

(1). 600dpi : 2.025~3.375ms/line

(2). 1200dpi : 4.05~6.75ms/line

B. System clock = 32MHz :

a. Normal Mode :

24x31.25ns/pixel = 0.75us/pixel

(1). 600dpi : 4.05ms/line

(2). 1200dpi : 8.1ms/line

b. Fast Mode :

9x31.25ns/pixel = 0.281us/pixel

12x31.25ns/pixel = 0.375us/pixel