Fig. 3-6- Page 48

CHAPTER 3  THEORY OF OPERATION

3-6

Fig. 3-6 shows the block diagram of the main PCB of the HL-1270N printer.

Reset Circuit

Program + Font ROM

4.0 Mbytes

RAM

(4.0 Mbytes)

Option RAM (SIMM)

(max. 32Mbytes)

EEPROM (4096 x 8 bits)

CPU Core

(MB86832)

A  S  I  C

Oscillator (32.7MHz)

Address Decoder

DRAM Control

Timer

FIFO

CDCC Parallel I/O

Soft Support

EEPROM I/O

Engine Control  I/O

To Engine PCB

BUS

INT

To PC

USB I/O

To PC

Flash ROM

(2.0 Mbytes)

PCI Bus Control

Network Board

To PC

or Hub

Fig. 3-6

HL-1270N