20 , 0,05 . , 0,2 . 1.
2 , .. 4 . 255 ( , 8- ). 255- 0. DECF , .. . :
255*4*0,2 + 2 *0,2=204,4
, .. 4 + :
4*0,2 + 204,4 = 205,2
, , , .
3 ˻ Assembler PIC16F877A
: , :
- 0,1 ;
- 3- PORTC;
- 2-
PORTD;
- , -
200 Timer1.
. , .
N = 100000/205,2=487
255. :
255*205 = 52275
:
100000/52275 = 2
. -, 1,14 . :
1140/ 52=22
1
include "p16f877A.inc"
Sch_in EQU H'22'; .
Sch_out equ H'23'; .
Sch3 equ H'24'; .
org h'00'
nop
nop
nop
org h'05'
Nach
clrf STATUS
clrf PORTC;
bsf STATUS,5
movlw B'00001111'
movwf TRISB; 0-3 PORTB
clrf TRISC; PORTC
clrf TRISD; PORTD
bcf STATUS,5
WaitPush
btfss PORTB,0; 1 RB0-
;
goto WaitPush
call Timer2;
bsf PORTC,3;
|
|
|
;
call Timer1; ,
goto Nach
goto $
Timer1
movlw D'200'; 2
movwf Sch_in; .
N_in
decf Sch_in,F; Sch_in 1.
btfss STATUS,Z; Sch_in , GOTO.
goto N_in; Z=0
return
Timer2
MOVLW d'2';
MOVWF Sch3; W .
N3
MOVLW D'255'; D'2'
MOVWF Sch_out; .
N_out; .
MOVLW D'255'; D'2'
MOVWF Sch_in; .
N_in; .
DECF Sch_in,F; Sch_in 1.
BTFSS STATUS,Z; Sch_in , GOTO.
GOTO N_in; Z=0.
DECF Sch_out,F; Sch_out 1.
BTFSS STATUS,Z; , GOTO.
GOTO N_out; Z=0.
DECF Sch3,F; Sch3 1,
BTFSS STATUS,Z; (Z=1), GOTO.
GOTO N3; Z=0.
RETURN; Timer2.
End
2 -7.
2 -7 1
3 4 PrtSc .
3 0 PORTC
4 0 PORTC ,
