32.768kHzの水晶発振子＋タイマー1へ

#include <pic.h>

__CONFIG(XT & WDTDIS & PWRTEN & BOREN & LVPDIS & UNPROTECT);

#define USE_TIMER_1

// 現在の時間
#define CURRENT_HOUR	4
#define CURRENT_MIN		17

#ifdef USE_TIMER_1
// タイマー1の設定
#endif // USE_TIMER_1

#ifdef USE_TIMER_0
// タイマーの設定
#define	PERIOD	1000000		// period in uS - one second here
#define	XTAL	4000000		// crystal frequency - 4MHz

#define IPERIOD	(4 * 1000000 / XTAL)	// Period of instruction clock in uSeconds

#define	SCALE	256		// Timer 0 prescaler
#define T0_TICKS 256	// Number of counts for interrupt

#define TICK_PERIOD (SCALE * IPERIOD)	// Period (uSec) of one increment of timer 0

#define	RELOADS	((PERIOD/T0_TICKS)/TICK_PERIOD)

near unsigned char reload = 0;
#endif // USE_TIMER_0

// GLOBALS
unsigned char dp;
unsigned char sec = 0;
unsigned char min = 0;
unsigned char hour = 0;
unsigned char selector = 0;

#ifdef USE_TIMER_1
void interrupt timer1itr(void)
{
	TMR1L = 0;
	TMR1H = 0x80;
	TMR1IF = 0;
	sec++;
	if (sec > 59) {
		sec = 0;
		min++;
		if (min > 59) {
			min = 0;
			hour++;
			if (hour > 23) {
				hour = 0;
			}
		}
	}
}
#endif // USE_TIMER_1

#ifdef USE_TIMER_0
void interrupt timer0_proc(void)
{
	if(reload == 0){
		// effect a change on PORTB whenever our desired period is reached.
		// Note this timing will contain a margin of error.
		if (sec & 1) {
			reload = RELOADS;
		} else if (sec & 2) {
			reload = RELOADS;
		} else {
			reload = RELOADS + 1;
		}
		sec++;
		if (sec > 59) {
			sec = 0;
			min++;
			if (min > 59) {
				min = 0;
				hour++;
				if (hour > 23) {
					hour = 0;
				}
			}
		}
	}
	reload--;
	T0IF = 0;
}
#endif // USE_TIMER_0

void delay(unsigned char t)
{
	for (unsigned char a = 0; a < t; a++) {
		for (unsigned char b = 0; b < 255; b++) {
		}
	}
}

void selectDigit(unsigned char sel)
{
	switch (sel) {
	case 0:
		RB0 = 0;
		RB1 = 1;
		RB2 = 1;
		RB3 = 1;
		RB4 = 1;
		RB5 = 1;
		break;
	case 1:
		RB0 = 1;
		RB1 = 0;
		RB2 = 1;
		RB3 = 1;
		RB4 = 1;
		RB5 = 1;
		break;
	case 2:
		RB0 = 1;
		RB1 = 1;
		RB2 = 0;
		RB3 = 1;
		RB4 = 1;
		RB5 = 1;
		break;
	case 3:
		RB0 = 1;
		RB1 = 1;
		RB2 = 1;
		RB3 = 0;
		RB4 = 1;
		RB5 = 1;
		break;
	case 4:
		RB0 = 1;
		RB1 = 1;
		RB2 = 1;
		RB3 = 1;
		RB4 = 0;
		RB5 = 1;
		break;
	case 5:
		RB0 = 1;
		RB1 = 1;
		RB2 = 1;
		RB3 = 1;
		RB4 = 1;
		RB5 = 0;
		break;
	default:
		RB0 = 1;
		RB1 = 1;
		RB2 = 1;
		RB3 = 1;
		RB4 = 1;
		RB5 = 1;
		return;
	}
}

void outputDigit(unsigned char val)
{
	switch (val) {
	case 0:
		PORTD = 0b00111111;
		break;
	case 1:
		PORTD = 0b00000110;
		break;
	case 2:
		PORTD = 0b01011011;
		break;
	case 3:
		PORTD = 0b01001111;
		break;
	case 4:
		PORTD = 0b01100110;
		break;
	case 5:
		PORTD = 0b01101101;
		break;
	case 6:
		PORTD = 0b01111101;
		break;
	case 7:
		PORTD = 0b00000111;
		break;
	case 8:
		PORTD = 0b01111111;
		break;
	case 9:
		PORTD = 0b01101111;
		break;
	default:
		PORTD = 0;
		break;
	}
}

void outputDP(unsigned char dp)
{
	if (dp) {
		RD7 = 1;
	} else {
		RD7 = 0;
	}
}

int main()
{
	// 時間設定
	hour = CURRENT_HOUR;
	min = CURRENT_MIN;
	// ポートの設定
	TRISB = 0xC0;	// 0, 1, 2, 3, 4, 5 出力
	TRISD = 0x00;	// 全部出力
	// ポートの初期化
	RB4 = 1;
	RB5 = 0;
	RB0 = 1;
	RB1 = 1;
	RB2 = 1;
	RB3 = 1;
#ifdef USE_TIMER_1
	// タイマー1の設定
	TMR1CS = 1;	// 0=内部クロック, 1=外部クロック
	T1CKPS1 = 0;
	T1CKPS0 = 0;
	T1OSCEN = 1;
	T1SYNC = 0;     // 0=同期, 1=非同期
	TMR1L = 0;
	TMR1H = 0x80;
	TMR1IF = 0;
	TMR1IE = 1;
	TMR1ON = 1;
	PEIE = 1;
	GIE = 1;
#endif // USE_TIMER_1
#ifdef USE_TIMER_0
	// タイマー0の設定
	OPTION = 0b0111;	// prescale by 256
	T0CS = 0;			// select internal clock
	T0IE = 1;			// enable timer interrupt
	GIE = 1;			// enable global interrupts
#endif // USE_TIMER_0
	while (1) {
		dp = sec % 2;

		selectDigit(99);
		outputDigit(10);
		outputDP(0);
		selectDigit(selector++);
		outputDigit(sec % 10);
		outputDP(dp);
		delay(1);

		selectDigit(99);
		outputDigit(10);
		outputDP(0);
		selectDigit(selector++);
		outputDigit(sec / 10);
		outputDP(0);
		delay(1);

		selectDigit(99);
		outputDigit(10);
		outputDP(0);
		selectDigit(selector++);
		outputDigit(min % 10);
		outputDP(0);
		delay(1);

		selectDigit(99);
		outputDigit(10);
		outputDP(0);
		selectDigit(selector++);
		outputDigit(min / 10);
		outputDP(0);
		delay(1);

		selectDigit(99);
		outputDigit(10);
		outputDP(0);
		selectDigit(selector++);
		outputDigit(hour % 10);
		outputDP(0);
		delay(1);

		selectDigit(99);
		outputDigit(10);
		outputDP(0);
		selectDigit(selector++);
		outputDigit(hour / 10);
		outputDP(0);
		delay(1);

		selector = 0;
	}
	return 0;
}