求用单片机设计一个秒表AT89C51
发布网友
发布时间：2023-04-09 05:43
共2个回答
热心网友
时间：2024-10-22 15:40
;汇编程序如下。
;使用T0定时方式1，每隔50ms中断一次，用于修改时间及显示
;使用外部中断0、1，用于控制启动和清零
;========================================================
ORG 0000H
AJMP MAIN
ORG 0003H
AJMP X0_INT
ORG 000BH
AJMP T0_INT
ORG 0013H
AJMP X1_INT
MAIN:
MOV TMOD,#01H ;T0定时方式1
MOV TH0, #(65536-50000) / 256 ;50ms@12MHz
MOV TL0, #(65536-50000) MOD 256;
SETB TR0
SETB ET0 ;开启定时中断
SETB EX0
SETB EX1
SETB EA ;定时器初始化结束，下面循环显示即可
MOV R1, #99H ;0~99计数.
MOV R7, #1 ;50ms计数.
MOV P0, #0C0H
MOV P2, #0C0H
LOOP:
SJMP LOOP
;-----------------------------------------------------------
DELAY: ;延时子程序.
AA4: MOV R4, #0
DJNZ R4, $
DJNZ R4, $
RET
;-----------------------------------------------------------
X0_INT: ;启动/停止
CPL F0
RETI
;-----------------------------------------------------------
X1_INT: ;清零
MOV R1, #0
MOV P0, #0C0H
MOV P2, #0C0H
RETI
;-----------------------------------------------------------
T0_INT: ;50ms中断执行一次.
MOV TL0, #(65536-50000) MOD 256;
MOV TH0, #(65536-50000) / 256 ;50ms@12MHz
DJNZ R7, T0_END ;中断不到20次.
MOV R7, #20
JNB F0, T0_END
MOV A, R1
ADD A, #1
DA A
MOV R1, A
ANL A, #0FH
MOV DPTR, #TAB
MOVC A, @A+DPTR ;查出段码
MOV P2, A
MOV A, R1
SWAP A
ANL A, #0FH
MOVC A, @A+DPTR ;查出段码
MOV P0, A ;显示十位数.
T0_END:
RETI
;-----------------------------------------------------------
TAB:
DB 0c0H,0f9H,0a4H,0b0H,99H,92H,82H,0f8H,80H, 90H
END
;===========================================================
;仿真截图如下：
热心网友
时间：2024-10-22 15:40
对不起，我不会用汇编做，所以用c语言编了一个，希望对你有帮助
#include <reg51.h>
#define uchar unsigned char
sbit start=P3^6;
sbit stop=P3^5;
uchar code latab[]={0x3f,0x06,0x5b,0x4f,0x66,
0x6d,0x7d,0x07,0x7f,0x6f,0x40}; //数字编码0-9
uchar code welatab[]={0xfe,0xfd,0xfb,0xf7,0xef,0xdf,0xbf,0x7f};//位控制字
uchar msec,sec,min;
void delay(uchar time) //延时
{
uchar i,j;
for(i=0;i<time;i++)
{
for(j=0;j<110;j++)
;
}
}
void writeled(uchar num,uchar addr)
{
//关显示
P2=0xff;
//送数据
P0=latab[num];
//开显示
P2=welatab[addr];
delay(4);
}
void display(uchar msec,uchar sec,uchar min)
{
uchar msech,msecl,sech,secl,minh,minl;
msech=msec/10;
msecl=msec%10;
sech=sec/10;
secl=sec%10;
minh=min/10;
minl=min%10;
writeled(minh,0);
writeled(minl,1);
writeled(10,2);
writeled(sech,3);
writeled(secl,4);
writeled(10,5);
writeled(msech,6);
writeled(msecl,7);
}
void init()
{
TMOD=0x10;
TH1=0xd8;
TL1=0xf0;
// TR1=1;
EA=1;
ET1=1;
}
void keyscan()
{
if(start==0)
{
delay(2);
if(start==0)
{
TR1=~TR1;
while(start==0)
{
display(msec,sec,min);
}
}
}
if(stop==0&&TR1==0)
{
delay(2);
if(stop==0)
{
msec=0;
sec=0;
min=0;
while(stop==0)
{
display(msec,sec,min);
}
}
}
}
void main()
{
init();
while(1)
{
display(msec,sec,min);
keyscan();
}
}
void timer1() interrupt 3
{
TH1=0xd8;
TL1=0xf0;
msec++;
if(msec==100)
{
msec=0;
sec++;
if(sec==60)
{
sec=0;
min++;
if(min==60)
{
min=0;
}
}
}
}
