%2.1 Control Board
2.1 Control Board
The control board consists of a single chip CPU, Program & Font ROMsone DRAM for the OL600e, two
DRAMs for the OL610ean 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 external bus, 25.54 MHz clock with input
frequency from a 12.27 MHz clock) which incorporates the MIPS 3000 RISC CPU and its peripheral
devices, and has the following functions:
Built-in device Function
Chip select controller
Bus controller
DRAM controller
Control of ROM DRAM and I/O device
DMA controller Transfer of image data from DRAM to video output port
Parallel interface controller Control of Centronics parallel interface
Serial interface controller Control of RS-232C serial interface
Video output port
LED STB output port Control of LED head
Timer Generation of various control timing signals
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
OL600e/610e
The Program & Font ROM stores the equipment program and various types of fonts. EPROM or 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).
OL610e/PS
The Program ROM & Font ROM store the HP4 emulation program and various types of fonts. Mask ROM
is used for a Program & Font ROM.
(3) DRAM
OL600e/610e
The DRAM is a resident memory1MB in the OL600e, 2MB in the OL610eused as a buffer; it stores edited
data, image data, DLL data, and macro data.
OL610e/PS
The DRAM is resident memory (2MB on the board plus 0.5MB on the PS board) used as a buffer; it
stores edited data, image data, DLL data, and macro data. In PostScript mode, it is used as VM and font
cache also.
(4) EEPROM
1,024-bit Electrically Erasable PROM (EEPROM), is loaded with the following data:
• Menu data • Various counter data (Page counter, Drum counter) • Adjusting parameters (LED head
drive time, print start position, paper feed length)
(5) Parallel Interface
Parallel data is received from the host system via parallel interface which conforms to the Centronics
specification. IEEE 1284 spcification bi-directional parallel is supported.
OKI OL600/610ex (96-01-18