Service manual

ManualsBrandsSharp ManualsBusiness equipmentCE-1600P

(2)

The HDS1202 L

CD

d

ri

ver

is

for

the

6800

series;

the

timing clock E required for this interface

is

sent

from

the SC7852.

The clock E goes high when

the

Z·80

acasses

40H-

5FH of

110.

(It has a half clock delay against

lORa

and its pulse

width

is

540

nanoseconds.)

But,

the

HDS1102 will

not

be $elected unless

all

three

chip select lines

(CST, CS2. CS3) are enabled. Two

HD61102s have

the

following address inputs as shown

in

the

next

table.

HD6tl02I1C2)

H06tl02

(ICl)

CSI

A2

A3

CS2

A' A'

C53

A'

M

Selected I/O 'PICe

SOH

- 53H

SOH

-53H

58H - 58H

54H - 57H

(3)

For

the

LCD

drive voltage,

VCC-VEE

are divided by

a resistor

to

obtain

the

LCD

drive voltages,

V1

......

V6

and VEE .

VEE

is

derived from

the

power

supply hybrid

IC

50347C.

V,

( H061203

(S)

, H061102 )

V)Rl

+

-

V.

( H061203 )

R2

+

-

RS

g:

V,

( H061102 )

V,

( H061203 )

R.

,

g:

R5 :

It

V.

( H061102 )

VR

I

V

V,

( H061203

(S)

, H061102 )

VEE

VEE

( H061203

(5)

,H061102 \

(=

- 8

.5V)

7·5. Keyboard block

7-5-1. Key scan timings

Keyboard key scan

is

done

by a Z·

80

i

nterrupt

with

a 1/64

second timer interru

pt

(subcontroller

output

INT4

).

7-6·2. Method

of

scanning

Ni

ne

key

strobe signals are

obtained

through PA7

......

PAO

and

P86 of

the

SC7B52 I/O

port

.

Key

scan

is

done

in

the

following ways:

<D

Only the

strobe

signal

of

the

Y row

to

be scanned

is

set

low with

ot

her

strobe

signals set for

the

input

mode.

®

To

,can another

strobe

r

ow

after

the

current

strobing

row, a high signal

is

issued

to

that

strobing row first,

-

13

-

then

set

in

the

input

mode

. So, a low signal

is

issued

to

PA7

,..,

PAO

and P86

at

every

1/64

second

to

discri·

minate a key depression. In this instance, a low signal

is

sent

to

all

strobe

lines

to

sense a key oepression.

When a key depression

is

sensed,

that

particular key

is

distinguished

after

sencling a strobe

to

each line.

As

the

key

input

appears

on

KIN7

......

KINO

of

the

SC78S2, a row

of

the

keys in a low

state

is

judged

to

be

the

r

ow

at

which

the

key

entry

occurred. Since i

nput

not

having a key

entry

is

internally pulled

up

in

the

LS

I, it

is

in a high level.

7-6. Buzzer block

7-6-1. General

These

two

lines activate

the

buzzer.

• PC6 o

utput

of

the

SC7852

•

Subcontro

ller

r-

output

Hi

·2. De.cription

As

the

buzz.er

is

sandwiched between

two

lines, oscillation

from

either

line causes

the

buzzer

to

activate. Consumption

current

is

3 mA, maximum.

(Conditions:

input

volta

ge·

4.5Vp-p square wave, i

nput

frequency · 4.1 KHz)

PC'

--@---

F

(1) PC6

The following three signal sources are

connected

to

this

line.

<D

PB2

..... Cassene playback signal

®

PC7

..... Cassette recording signal and beep by a

BEEP

statement

®

SOC

..... Recording signal by

the

CE·150 or

CE

o

162E

But, when

the

beep

is

turned off, sound

is

not

generated

no

matter

what

the

above signals may be.

The above

three

signal lines are normally high.

12)

F

The following three

Signal

sources are connected

to

this

line.

(!)

Click .... In

the

click mode, a click

is

generated

each time a key

is

pushed.

@

Sound

generated upon wake·up.

® Sound generated before issuing an alarm message.

Normally, these

three

lines are low.

7·7.

RS

·232C interface and SIO interface

The following $erial interfaces are provided for

the

PC

-

1600.

(1)

RS

·2

32C

interface

(COM

1:)

(2)

510

interface (COM2:)

It incorporates

the

UART TC8576T as

the

hardware.

While

the

PC·

1600 has two interfaces with single supported

channel, only

one

interface can be active

at

one

time. The

OP

EN

or

SETOEV s

tatement

is

used

to

selectively activate

the

channel and

the

PRIME signal

is

used

to

activate

the

hardware.