Control Circuit; Control Circuit Overview - Epson Perfection 1200U Service Manual

EPSON Perfection 1200

2.3 Control Circuit

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


SCSI Model: B104 Main Board


USB Model: B104 Main-B Board
The difference is the only interface part with host.

2.3.1 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 (IC10) at 20MHz frequency. Image
data processing, correction, CCD sensor board, A/D converter control are
operated at ASIC (IC8). Table 2-3 shows major IC functions.
Operating Principles
IC
M37920
E02A31EA
MB81F64842C
IS61C256AH
VSP3010Y
A3957SLB
M51953A
MBM28F200B
BH9596FP-Y
SPC721F0A
E02A29BB
BA033FP-EL
SSR20.00BR
SSA20.00BR
Control Circuit
Table 2-3. Major ICs
Location Function
CPU
IC10 24-bit Address Bus
16-bit Data Bus
ASIC
• CCD Control
IC8 • Line (sharpness) Control
• Image Processing
• Memory Control
IC12 SDRAM 64Mbit
SRAM 32k x 8 bit
IC7, IC11
IC15 12-bit A/D converter
IC4, 5 CR motor driver IC
IC9 Reset IC
IC6 Flash ROM 128k x 16bit
IC14 Terminator (SCSI mode only)
IC13 SCSI Controller (SCSI mode only)
IC13 USB Controller (USB mode only)
IC3 3.3VDC (LV1)
CR1 20MHz clock for E02A31EA
CR2 20 MHz clock for CPU
Revision B
23