Brother International HL 760 Service Manual - Page 14

(8)

CDCC

parallel

I/O

<Data

receiving>

There

are

two

modes

in

this

unit.

One

is

the

CPU

receiving

mode

and

the

other

is

the

DMA

receiving

mode.

In

the

CPU

receiving

mode

the

CPU

receives

the

command

data

from

the

PC,

and

after

the

CPU

is

switched

to

the

DMA

mode,

it

receives

the

image

data

and

writes

to

the

DRAM

directly.

CPU

Receiving

Mode

(

9

)

STROBE

BUSY

ACK

I

I

I

I

1

DMA

Receiving

Mode

STROBE

BUSY

ACK

90

μsec

1

1

0.5

μsec

I

I

I

I

I

I

1.5

μsec

0.5

μsec

BUSY

goes

HIGH

at

the

falling

edge

of

STROBE.The

data

(8

bits)

from

the

PC

is

latched

in

the

data

buffer

at

the

rising

edge

of

STROBE.

The

pulse

width

of

ACK

differs

according

to

the

speed

MODE

as

shown

above.

BUSY

goes

LOW

at

the

rising

edge

of

ACK.

<IEEE1284

support>

This

supports

the

IEEE1284

data

transfer

with

the

following

mode.

Nibble

mode

Byte

mode

ECP

mode

Data

extension

This

circuit

extents

the

compressed

image

data

which

are

received

from

the

PC,and

writes

the

bit

map

data

to

the

FIFO.

(10)

Software

support

Supports

16

x

16

rotation,

bit

expansion,

bit

search,

and

decimal

point

change.

(11)

EEPROM

I/O

One

output

port

and

one

I/O

port

are

assigned.

II

-

5

Brother International HL 760 Service Manual - Page 14

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