Oki 6E, 6ex specifications Control Board

2.1Control Board

The control board consists of a single chip CPU, Program & Font ROM's, one or two DRAMs, an EEPROM, a host interface circuit, and a mechanism driving circuit.

(1)Single chip CPU

The single chip CPU is a custom CPU (32-bit internal bus, 16-bit or 32-bit external bus, 25.54 MHz clock with input frequency from a 12.27 MHz clock) which incorporates the RISC CPU and its peripheral devices, and has the following functions:

Built-in device	Function
Chip select controller	Control of ROM, DRAM and I/O device
Bus controller
DRAM controller
DMA controller	Transfer of image data from DRAM to video output port
Parallel interface controller	Control of Centronics parallel interface
Video output port	Control of LED head
LED STB output port
Timer	Generation of various control timing
	Monitoring of paper running and paper size
Serial I/O port	Control of operator panel, EEPROM, and options
I/O port	Input and output of sensor and motor signals

(2)Program & Font ROM OKIPAGE 6e/6ex

The Program & Font ROM store the PCL5e emulation program and various types of fonts. Mask ROM is used for a Program & Font ROM. The mounting location of this Program & Font ROM varies depending on the type of ROM (for the mounting location see 7.2).

PS Board

The Program & Font ROM store the PostScript program and various types of fonts. Mask ROM is used for a Program & Font ROM (for the mounting location see 7.3).

2 - 4