MPXM2010GS datasheet(20/24 Pages) FREESCALE

20 / 24 page

AN1950

Sensors

Freescale Semiconductor

;

delmain: main delay routine; generates delay equal to H:X x 20us

;

-------

delmain: mov #$36,tsc

;stop TIM & / 64

sthx tmodh

;count H:X x 20us

bclr 5,tsc

;start clock

delwait: brclr 7,tsc,delwait ;wait for end of countdown

pulx

pulh

rts

;this RTS serves for all delay routines!

;-------- A/D Routines ----------------------------------------------

;

adcbyti: gets single A/D reading from PTA0 and returns it in A

;

-------

adcbyti: mov #$00,adscr

;ADC set to PTA0

brclr 7,adscr,*

;wait for ADC reading

lda adr

;result in adr

rts

;- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

;

adcbyta: gets averaged A/D reading from PTA0 and returns it in A

;

-------

adcbyta: clr CNT

;average 256 readings

clr RB

;will be addint them up

clr RA

;in RB:RA

do256a: bsr adcbyti

add RA

sta RA

lda RB

adc #$00

sta RB

;16-bit add into RB:RA

dbnz CNT,do256a

;do all 256

lsl RA

;if RA<$80

bcc nochga

;then RB result is correctly rounded

inc RB

;otherwise round off to next value

nochga: lda RB

rts

;-------- LCD Routines ----------------------------------------------

;

lcdinit: initializes LCD

;

-------

lcdinit: lda #$3C

;set 8-bit interface, 1/16 duty, 5x10 dots

bsr lcdcmdo

lda #$0C

;display on, cursor off, blink off

bsr lcdcmdo

lda #$06

;increment cursor position, no display shift

bsr lcdcmdo

lda #$01

;clear display

bsr lcdcmdo

rts

;- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

;

lcdcmdo: sends a command to LCD

;

-------

lcdcmdo: bsr shiftA

bclr 4,porta

;RS=0 for command

bset 3,porta

bclr 3,porta

;toggle E

bsr del5ms

;some commands require 2ms for LCD to execute

rts

;so let's play it safe

;- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

;

lcdchro: sends a character (data) to LCD

;

-------

lcdchro: bsr shiftA

bset 4,porta

;RS=1 for data

MPXM2010GS Fiches technique(PDF) 20 Page - Freescale Semiconductor, Inc

MPXM2010GS Fiches technique(HTML) 20 Page - Freescale Semiconductor, Inc

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

Fiches technique Télécharger

Lien URL