Epson Stylus Photo785EPX, Service Manual

Page: 50 / 192

EPSON Stylus PHOTO 895/785EPX/915/825 Revision B
Operating Principles Electrical Circuit Operating Principles 50
2.2.2.1 Main elements
Following table provides the description of main element functions on the C408/C498
MAIN board.
Table 2-9. Main Elements (Printer section)
IC Location Function
CPU-ASIC 2in1
E01A22C*
IC2
16bit CPU mounted on the MAIN board is driven by
clock frequency 24MHz and controls the printer
PROM IC3
• Capacity 4/8/16MB, Bus= 16 bit
• Program for CPU or PCG
DRAM IC5, IC4 Bus= 16 bit, 4Mbit DRAM and 16Mbit DRAM
RTC9822
(Reset function,
RTC, EEPROM
compound IC)
IC6
EEPROM section
• Default value setting
• Parameter backup
RESET section
• For +3.3V; reset when +2.5V is detected
• For +5V; reset when +4.2 is detected
• For +42V; reset when +36 is detected
TIMER section
• Electric double layer capacitor (0.33F) is used.
Common Driver IC12
Head drive control HIC
• Generates head common voltage.
Motor Driver IC9 CR motor drive IC
Motor Driver IC11 PF motor drive IC
Motor Driver IC10 ASF motor drive IC
Table 2-10. Main Elements (Printon section)
IC Location Function
CPU
V832
IC15
• USB storage class target
• PCMCIA control
• Image processing
• Operating frequency: 47.6 MHz
ASIC1
E05B75B*
IC22
• Package: 208pinPQFP
• Operating frequency: 47.6 MHz and 48 MHz
ASIC2
E09A31A*
IC17
• Data communication with the printer section
• Start and finish of DMA by MWPACKU
• SW condition is read from the printer PNL and
monochrome PNL.
• SW condition to the printer side is set from the CPU
and can be output.
• JFK image processing
• Fraction processing function applicable to the MW
packing function
• Clock synchronous serial interface
• The maximum 160 bit data are serial-exchanged and
transmitted to the LCD drive.
PCMCIA Socket
Power Controller
MAX1602
IC23
• Package: 16 pin S.O Package
Flash ROM
MBM29LV160TC/
BC
IC24
• Capacity: 16/8Mbit Bus=16bit
• Program
SDRAM
K4S641632D
IC18
• Capacity: 64Mbit (1M x 16bit x 4bank), Bus=16bit
• System memory
USB HUB IC
TUSB2036VF (TI)
IC20
• Self power/pass power mode
• Applicable to full speed/low speed related to all
Down Stream ports
• Applicable to the suspend/resume operation
• Suspend/status output