Control Circuit; Control Circuit Overview - Epson GT-7000 Service Manual

EPSON GT-7000

2.1.4 Control Circuit

There are 2 types of control circuit boards due to the interface
specification.

SCSI Model:B071 Main Board

USB Model: B071 Main-B Board
The difference is the only interface part with host.
C C D B o a r d
L a m p
&
I n v e r t e r B o a r d
Rev. A
I m a g e D a t a
( R / G / B )
C o n v e r t e r
A M P .
( I C 2 4 )
R e s e t I C
( I C 7 )
C R M o t o r
C R
M o t o r
Figure 2-6. Control Circuit Block Diagram (SCSI)

2.1.4.1 Control Circuit Overview

Figure 2-6 is SCSI control circuit block diagram, and Figure 2-7 is for
USB. This scanner uses the one-tip 16-bit bus CPU(IC22) at 20MHz
frequency. Image data processing, correction, CCD sensor board, A/D
converter control are operated at ASIC(IC21). Table 2-3 shows major IC
functions.
S R A M
( I C 8 , I C 1 2 )
1 2 - b i t
A / D D a t a
E 0 2 A 2 8 ( I C 2 1 )
S C S I C o n t r o l l e r
( I C 1 3 )
P R O M
D r i v e r
C P U ( I C 2 2 )
( I C 1 )
Chapter 2 Operating Principles
D - R A M
I C 1 9 , I C 2 0 )
C L K ( C R 1 )
3 . 3 V
R e g u l a t o r
( I C 1 0 )
8 - b i t D a t a
S C S I
T e r m i n a t o r I C
( I C 5 )
( I C 1 4 )
C L K ( C R 2 )
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