(Canoscan Fb330P; (Canoscan Fb630P - Canon CANOSCAN FB330 series Service Manual

CHAPTER 2
IV. CONTROL SYSTEM
A. CanoScan FB330P/FB630P
1. Outline
CanoScan FB330P/FB630P control system consists of the CPU and gate array. The CPU
has 7 digital ports. P0, P2, P3, P6, and P7 are for generating control signals in the main PCB.
P4 is for address bus and data bus (AD-AD7) and P5 is for address bus (A8-A15). P7 is mainly
for inputting a function check mode setting.
Control signal
2. Control Switching Between Printer And Scanner
CanoScan FB330P/FB630P has two parallel ports which allow to connect in order of the
host computer, scanner and printer as shown in Figure 2-30. When the host computer sends
the signal to start the communication with the scanner, the control is switched between printer
and scanner.
Host computer
The host computer sends the command to select the scanner or the printer to communicate
with.
2 - 38
COPYRIGHT © 1999 CANON INC. CANOSCAN FB330/FB630 SERIES REV.0 OCT. 1999 PRINTED IN JAPAN (IMPRIME AU JAPON)
CPU
P5
A8~15
P4
P0, P2, P3,
AD0~7
P6, P7
Figure 2-29
Scanner
Figure 2-30
Gate Array
To host computer
Printer