Application Circuits

Note:

The connection of IRQ and RD pin can be selected depending on the requirement of the MCU.

W±20%.

Adjust R (external pull-high resistance) to fit user

¢s time base clock.

Command Summary

Name

ID

Command Code

D/C

Function

Def.

READ

110

A5A4A3A2A1A0D0D1D2D3

D

Read data from the RAM

WRITE

101

A5A4A3A2A1A0D0D1D2D3

D

Write data to the RAM

READ-MODIFY-

WRITE

101

A5A4A3A2A1A0D0D1D2D3

D

Read and Write data to the RAM

SYS DIS

100

0000-0000-X

C

Turn off both system oscillator and LCD bias

generator

Yes

SYS EN

100

0000-0001-X

C

Turn on system oscillator

LCD OFF

100

0000-0010-X

C

Turn off LCD display

Yes

LCD ON

100

0000-0011-X

C

Turn on LCD display

TIMER DIS

100

0000-0100-X

C

Disable time base output

Yes

WDT DIS

100

0000-0101-X

C

Disable WDT time-out flag output

Yes

TIMER EN

100

0000-0110-X

C

Enable time base output

WDT EN

100

0000-0111-X

C

Enable WDT time-out flag output

TONE OFF

100

0000-1000-X

C

Turn off tone outputs

Yes

CLR TIMER

100

0000-1101-X

C

Clear the contents of the time base generator

CLR WDT

100

0000-1111-X

C

Clear the contents of WDT stage

RC 32K

100

0001-10XX-X

C

System clock source, on-chip RC oscillator

Yes

EXT 32K

100

0001-11XX-X

C

System clock source, external clock source

TONE 4K

100

010X-XXXX-X

C

Tone frequency output: 4kHz

TONE 2K

100

0110-XXXX-X

C

Tone frequency output: 2kHz

IRQ DIS

100

100X-0XXX-X

C

Disable IRQ output

Yes

IRQ EN

100

100X-1XXX-X

C

Enable IRQ output

HT1622

Rev. 1.40

10

February 6, 2007

B Z

I R Q

H T 1 6 2 2

D A T A

1 / 4 B i a s , 1 / 8 D u t y

C S

R D

W R

L C D P a n e l

C O M 0 ~ C O M 7

S E G 0 ~ S E G 3 1

B Z

*

R

*

P i e z o

V R

*

V D D

V L C D

M C U