Application Circuits

Host controller with an HT1621 display system

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

Adjust R (external pull-high resistance) to fit user s time base clock.

HT1621

17

April 21, 2000

IR Q

DA T A

*

O n - c hi p O SC

OSC I

OSC O

C l o ck O u t

E x te r n a l C o l c k 1

E x te r n a l C o l c k 2

CS

RD

WR

m C

C r yst a l

3276 8H z

H T 1621B

LC D P a ne l

BZ

BZ

C O M 0 ~ C O M 3

SEG 0 ~ SEG 3 1

Pi e z o

1/ 2 or 1 / 3 B i a s ; 1 / 2 , 1/ 3 or 1 / 4 D ut y

R

*

VR

*

VD D

VL C D