Epson DFX-8500 - Impact Printer, Service Manual

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OPERATING PRINCIPLES
Rev. B
2-19
Table 2-5 describes the functions of the main components on the C204 MAIN and C204 DRV board.
Table 2-5. Main IC Functions
Board IC Name Location Functions
C204 MAIN TMP95C061
(CPU) IC2 Receives data from the host computer via the gate array, loads
the data to the input buffer in the RAM, and converts the image
data to print data.
E05B36
(Gate Array) IC1 The main features are:
•
/CS (Chip Select) signal creation
•
Address decoding
•
Address latching
•
Clock pulse creation
•
Printhead driver control
•
CR motor driver control
•
CR and PG motor pulse encoder I/O (input/output)
•
Encoder pulse I/O
•
Phase signal creation for the motors
•
I/O port control
•
Interface control
•
Abnormal CR and PF motor detection
•
/RESET signal creation
PROM IC5 Contains the program that runs the CPU.
RAM IC14 Holds the CPU working area and buffers (input,, line,, and
image buffers).
EEPROM IC11 Memorizes the printer unique parameter during the power is off.
ADM232 IC9 EIA to Logic level voltage level converter
PST591D IC13 System reset IC
C204 DRV STK681-050 IC1 Drives the CR motor.
STK67138MK4 IC2 Drives the PF motor.
uPC393C IC3 Detects the current in the CR motor driver and feeds it back to
the gate array on the C204 MAIN board.