AN594 datasheet(12/28 Pages) STMICROELECTRONICS

12 / 28 page

Direct LCD Drive

12/28

;**************************************************************************

INITIALIZATION SUBROUTINE

;**************************************************************************

.ORG 880h

DEBUT

RETI

; END OF RESET INTERRUPT

LDI

DDRA,0C7H

; A0 to A2 PUSH PULL OUTPUT = 0

LDI

ORA,0C7H

; A3 to A5 pull up input ; A6 & A7 output = 0

LDI

DRA,00H

; A3 to A5 for keyboard

; A6 -> BP1, A7 -> BP2

LDI

COPYA,00H

LDI

DDRB,0FFH

; B0 A B7 push pull output = 0

LDI

ORB,0FFH

; port B controls LC Display

LDI

DRB,00H

;

LDI

COPYB,00H

;

LDI

DDRC,00H

;

LDI

ORC,00H

; C4 C5 C6 C7 unused inputs

LDI

DRC,00H

;

LDI

COPYC,00H

;

LDI

DWR,3CH

; origin of the table

LDI

FLAGS,00h

; reset flags

;**************************************************************************

END OF INITIALIZATION SUBROUTINE

;**************************************************************************

MAIN LCD DRIVE SUBROUTINE

task : generate alternative signals to control LCD backplanes BP1/BP2

drive the segments of the LCD

calculate duration of each duration phase

;**************************************************************************

SOMMEIL

RES

0,FLAGS

LDI

ORA,0CFh

; A3 becomes interrupt input

LDI

IOR,10h

; valid interrupt

STOP

; wait at ON/OFF button activation

LDI

ORA,0C7h

;

CLR

IOR

; inihibit INTERRUPTS

CALL CLAVIER

; keyboard test

JRR

0,FLAGS,SOMMEIL

; IF no push on ON/OFF button , THEN stand by

I1BOUCLE RES

0,FLAGS

; ELSE INITIALIZATION of MAIN LOOP

LDI

TOUCHU,00h

; ON/OFF FLAG is reset, UNITEE A 0

LDI

TOUCHD,00h

; reset M.S. DIGIT

LDI

IOR,10h

; valid interrupts

;**************************************************************************

BOUCLE1

LDI

TCR,18

; initialization of timer

LDI

TSCR,7Fh

; program it at 1,5 ms

A,TOUCHU

; determine data/rom window address

SLA

;

SLA

; multiply TOUCHU by 4

TABU,A

; initialize data/rom address

A,TOUCHD

; of TABLES 1 & 2

SLA

;

SLA

;

TABD,A

;

CALL DATALCD

; determine segments driver byte for PHASE 1

LDI

ORA,47h

; BP1 = Vdd ; BP2 =

Vdd/2 therefore

LDI

DDRA,47h

; A6 becomes push pull output at VDD

LDI

DRA,0C0h

; A7 becomes high impedance input

DRB,A

; load segments driver byte on port

CALL CLAVIER

; test of keyboard

WAIT

;***************************************************************************

ANNEX 1: Software of the ST6215x based application (Continued)

AN594 bảng dữ liệu(PDF) 12 Page - STMicroelectronics

AN594 bảng dữ liệu(HTML) 12 Page - STMicroelectronics

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28

bảng dữ liệu tải về

Link URL