Main Control Board (Board-Com) - OKIDATA OKIPAGE 16n Service Manual

2.1

Main Control Board (BOARD-COM)

The control board consists of an one chip CPU, LSIs, 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, 32-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
Parallel interface controller
Timer
Serial I/O port
I/O port
Option I/O interface
(2) Program/font ROM's
The program/font ROM's store the HP IV emulation program and various types of font.
MASK ROM is used as the program/font ROM's.
Operation Description
Control of ROM, DRAM and I/O device
Transfer of image data from DRAM to OST LSI
Control of Centronics parallel interface
Generation of various control timing
Monitoring of paper running and paper size
Control of operator panel, EEPROM, and options
Inputting/outputting of sensor, signal and motor signal
Control of OKI HSP interface
2 - 3
Function
OKIPAGE 16n
Service Manual, P/N 59274401