Main Control Board (Board-Fff) - Oki OKIPAGE24DX Maintenance Manual

2.1

Main Control Board (BOARD-FFF)

The control board consists of an one chip CPU,a LSI, program/font ROM's, DRAM's, an
EEPROM, a host interface circuit, and a mechanism driving circuit.
(1) One-chip CPU
The one-chip CPU is a custom CPU (32-bit internal bus, 32-bit external bus, 120-MHz clock)
that incorporates an RISC CPU and its peripheral devices, and has the following functions.
Built-in device
Chip select controller
Bus controller
DRAM controller
DMA controller
Serial interface controller
Parallel interface controller
Timer
Serial I/O port
I/O port
Motor driver controller
Image processing circuit
(2) Program/font ROM's
• PCL ROM
The program/font ROM's store the HP LJ5 emulation program and various types of font.
MASK ROM is used as the program/font ROM's.
• PS ROM
The program/font ROM's store the Adobe PostScript Level 2 program and its fonts.
40930701TH DRAFT Vesion
Function
Control of peripheral LSI, ROM, DRAM and I/O device
Transfer of data from Host I/F to RAM
Control of RS232C serial interface
Control of Centronics parallel interface
Generation of various control timing
Monitoring of paper running and paper size
Control of serial interface between controller and operator panel, EEPROM
Control of a serial interface between controller and power supply board
Inputting of various sensor signals
Outputting of various control signals
Control of Main Motor
Executes the image data process for printing.
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