Application Circuits

Host Controller with an HT1647 Display System

*Note: The connection of IRQ and RD pin can be selected depending on the MCU.

W± 20%.

It is recommended to select 1/5 bias to fit TN-type, STN-type LCDs and select 1/4 bias to fit ECB-type LCDs.

Adjust R (external pull high resistance) to fit user

¢s time base clock.

Instruction Set Summary

Name

Command Code

D/C

Function

Def.

READ

A8110-A7A6A5A4A3A2A1A0D3D2D1D0

D

Read data from the RAM

WRITE

A8101-A7A6A5A4A3A2A1A0D3D2D1D0

D

Write data to the RAM

READ-MODIFY-

WRITE

A8101-A7A6A5A4A3A2A1A0D3D2D1D0

D

Read and Write data to the RAM

SYS DIS

X100-0000-0000-XXXX

C

Turn Off both system oscillator and LCD bias

generator

Yes

SYS EN

X100-0000-0001-XXXX

C

Turn On system oscillator

LCD OFF

X100-0000-0010-XXXX

C

Turn Off LCD display

Yes

LCD ON

X100-0000-0011-XXXX

C

Turn On LCD display

TIMER DIS

X100-0000-0100-XXXX

C

Disable time base output

Yes

WDT DIS

X100-0000-0101-XXXX

C

Disable WDT time-out flag output

Yes

TIMER EN

X100-0000-0110-XXXX

C

Enable time base output

WDT EN

X100-0000-0111-XXXX

C

Enable WDT time-out flag output

TONE OFF

X100-0000-1000-XXXX

C

Turn Off tone outputs

Yes

CLR TIMER

X100-0000-1101-XXXX

C

Clear the contents of the time base generator

CLR WDT

X100-0000-1111-XXXX

C

Clear the contents of the WDT stage

TONE 4K

X100-0001-0000-XXXX

C

Turn on tone output, tone frequency output:

4kHz

TONE 2K

X100-0001-0001-XXXX

C

Turn on tone output, tone frequency output:

2kHz

HT1647

Rev. 1.40

14

November 9, 2010

PATENTED

I R Q

D B 0 ~ D B 3

*

O n - c h i p O S C

O S C I

O S C O

C l o c k O u t

E x t e r n a l C l o c k 1 ( 3 2 k H z )

E x t e r n a l C l o c k 2 ( 3 2 k H z )

C S

R D

W R

C r y s t a l

3 2 7 6 8 H z

H T 1 6 4 7

L C D P a n e l

B Z

B Z

C O M 0 ~ C O M 1 5

S E G 0 ~ S E G 6 3

* 1 / 5 B i a s ( o r 1 / 4 B i a s ) , 1 / 1 6 D u t y

R*

V R

*

V D D

V L C D

P i e z o

M C U