/*************************************************
file name: prog4.c
function: 7-Segment LED display
Timer Interrupt(1ms) :
7-Segment Display(Scan): 012345
static LED(8) increment
Main routine : RUN LED toggle
1999.11.10. By KMD-KCO
**************************************************/
#include "io51.h"
#define BYTE unsigned char
#define WORD unsigned int
#define RUN_LED T0 /* define RUN_LED = T0 */
#define TMR_CLK_1M -922 /* 1msec : (11.0592MHz / 12) * 1 msec = 921.6 */
#define TMR_CLK_10M -9216 /* 10msec: (11.0592MHz / 12) * 10 msec = 9216 */
#define SEG_DATA(val) (((BYTE *)0x010000)[0x6000] = val)
#define SEG_SCAN(val) (((BYTE *)0x010000)[0x6002] = val)
#define S_LED(val) (((BYTE *)0x010000)[0x6006] = val)
const BYTE seg_font[] = /* HEX font */
{0xc0,0xf9,0xa4,0xb0,0x99,0x92,0x82,0xf8,0x80,
0x90,0x88,0x83,0xc6,0xa1,0x86,0x8e};
const BYTE seg_blank = 0xff; /* ' ' */
const BYTE seg_bar = 0xbf; /* '-' */
const BYTE seg_all_on = 0x00; /* '8.' */
const BYTE seg_scan[] =
{ 0x01,0x02,0x04,0x08,0x10,0x20,0x40,0x80 };
BYTE seg_data[7];
BYTE scan_cnt=0;
int i_cnt=0, m_cnt=0;
void init_timer(){
TMOD = 0x01; /* timer0:모드1(16비트),타이머, */
TL0 = TMR_CLK_1M & 0xff; /* Timer cnt Low value reload */
TH0 = TMR_CLK_1M >> 8; /* Timer cnt High value reload */
TR0 = 1; /* timer0 run */
ET0 = 1; /* enable timer0 overflow interrupt */
}
8051-실습-7Segment 동작원리와 구동 프로그램
- 5 -
㈜케이엠데이타
interrupt [0x0B] void T0_int (void){/* Timer 0 Interrupt routine */
TL0 = TMR_CLK_1M & 0xff; /* Timer cnt Low value reload */
TH0 = TMR_CLK_1M >> 8; /* Timer cnt High value reload */
i_cnt++; /* increment i_cnt */
S_LED(~i_cnt); /* static LED display */
/* 7segment */
SEG_SCAN(0); /* SEG OFF */
SEG_DATA(seg_data[scan_cnt]); /* Seg Data out */
SEG_SCAN(seg_scan[scan_cnt]); /* Seg Scan out */
scan_cnt++;
if(scan_cnt >= 7) scan_cnt = 0;
}
void main(){
int i;
init_timer(); /* Initialize timer */
EA = 1; /* Enable Global Interrupt */
seg_data[0] = seg_font[0]; /* 0xc0 = 0 */
seg_data[1] = seg_font[1]; /* 0xf9 = 1 */
seg_data[2] = seg_font[2]; /* 0xa4 = 2 */
seg_data[3] = seg_font[3]; /* 0xb0 = 3 */
seg_data[4] = seg_font[4]; /* 0x99 = 4 */
seg_data[5] = seg_font[5]; /* 0x92 = 5 */
seg_data[6] = 0x00; /* All LED ON */
while(1){
m_cnt++; /* Increment m_cnt */
RUN_LED ^= 1; /* Toggle RUN_LED */
for(i=0;i<10000;i++); /* Simple delay routine */
}
}