Brother International HS-5300 Service Manual - Page 25

1.3.3

Print

Head

Control

(1)

ASIC

2

The

MB87A133

is

used

as

the

ASIC

to

control

the

print

head.

The

ASIC

becomes

the

bus

master

instead

of

the

main

CPU

during

the

print

process

and

reads

the

converted

image

data

from

the

DRAM

based

on

the

encoder

signal

and

conditions

sent

from

the

main

CPU

and

engine

CPU.

It

also

sends

the

data

to

the

head

and

outputs

the

ink

jet

timing

to

the

head

drive

circuit.

This

ASIC

includes

the

following

functions

in

addition

to

the

print

head

control.

•

Extended

I/O

of

the

engine

CPU

•

MIO

interface

•

Timing

generating

circuit

for

the

ink

sensor

•

Carriage

motor

drive

timing

generating

circuit

1.3.4

Engine

Control

(1)

Engine

CPU

The

μPD784021GC,

a

16bit

one

-chip

microprocessor,

is

used

for

the

engine

control.

The

engine

CPU

controls

the

following.

•

Carriage

motor

control

•

PA

motor

control

•

Fan

motor

control

•

Inputs

and

outputs

from/to

the

operator

panel

•

Heater

control

•

Sensor

inputs

(2)

ROM

The

HM27C101AG-12

or

equivalent,

a

1

Mbit

(131072

-word

x

8bits)

EP

-ROM,

is

used

to

store

the

program

and

data

for

the

engine

CPU.

(3)

EEPROM

A

4Kbits

EEPROM

(X24C04

or

equivalent)

is

used

to

store

certain

conditions.

When

the

main

CPU

reads/writes

the

data

from/to

the

EEPROM,

the

main

CPU

communicates

with

the

engine

CPU

and

the

engine

CPU

actually

reads

and

writes

the

data.

11-6

Brother International HS-5300 Service Manual - Page 25

Brother International HS-5300 Manual

Page 25 highlights