//-----------------------------------------------------------
//              Nixie Clock Kennel Method CD11 Version
//		2004/01/25
//              kennel.org
//-----------------------------------------------------------

#pragma PROC_CODE_WORD_VAL 	0x3ffa
#pragma INTERRUPT_LOC      	0x04   // 割り込みベクタアドレス
#pragma INTERRUPT_SAVE_LOC 	0x0c   // 

#include "16F84.h"

//*****************************
// define
//*****************************

# define TRUE 			1
# define FALSE			0

//-- intcon Bits --

# define intcon_GIE		0x7
# define intcon_EEIE		0x6
# define intcon_T0IE		0x5
# define intcon_INTE		0x4
# define intcon_RBIE		0x3
# define intcon_T0IF		0x2
# define intcon_INTF		0x1
# define intcon_RBIF		0x0

//-- option Bits --

# define option_NOT_RBPU	0x7
# define option_INTEDG		0x6
# define option_T0CS		0x5
# define option_T0SE		0x4
# define option_PSA		0x3
# define option_PS2		0x2
# define option_PS1		0x1
# define option_PS0		0x0

// -- Interrupt bit --
# define RTCC_ZERO		intcon_T0IE	// 0x20
# define GLOBAL			intcon_GIE	// 0x80

int	 	tmr0   @ 0x01;
int 		porta  @ 0x05;
int 		portb  @ 0x06;
int 		intcon @ 0x0B;
int 		option @ 0x81;
int 		trisa  @ 0x85;
int 		trisb  @ 0x86;

//
// Global Value
//

unsigned int digit[6];
int i ,k ,t ,sinc;
long ssec, ksec, tsec, dsec, j;

//*****************************
// Idle Loop 
//*****************************
pause(t)
unsigned int t;
{
unsigned int d;

while( t ) {
	for(d = 0 ; d < 255 ; d++ );
	t--;
	}
}

// Timer Interrupt Routine (Clock Count Up)

__interrupt()
{
	asm(BCF intcon, 0x2);   // Clear tmr0 Overflow Flag
	ssec++;
	if (ssec >= 3125) {
		ssec = 0;
		sinc = 1;
		dsec++;
		if (dsec >= 480) {
			dsec = 0;
			}
		}
}

// Nixie Clock Main (Nixie Dynamic Drive, Setup)
main()
{

//  初期化

	ssec = 0;
	ksec = 0;
	option = 0x01;			// Pullup enable, Prescaler TM0, Scale Factor 4

	trisa  = 0xff;			// Port A all input
	trisb  = 0x0;			// Port B all output
	
	portb=0;			// Clear Port B
	tmr0 = 0;			// 12.8M / 4 * 256 = 3125Hz

	intcon |= (1 << RTCC_ZERO);	// Enable Timer 0 Interrupt
	intcon |= (1 << GLOBAL);	// Enable Interrupt

	for (i = 0 ; i < 7 ; i++) {
		digit[i] = 0;
	}

//  Main Loop

	while(TRUE) {
		for (i = 0 ; i < 5 ; i++) {
			k = porta;
			if (k > 7 && i != 4 ) {
				t = dsec % 8;
				if (t == 0 || t == 1 || t == 2) {
					switch (i) {
						case 0 :
						j = (digit[0] * 16) + 0;
						break;
						case 1 :
						j = (digit[1] * 16) + 1;
						break;
						case 2 :
						j = (digit[4] * 16) + 2;
						break;
						case 3 :
						j = (digit[5] * 16) + 3;
					}
				}
				else if (t == 3) {
					switch (i) {
						case 0 :
						j = (digit[0] * 16) + 0;
						break;
						case 1 :
						j = (digit[1] * 16) + 1;
						break;
						case 2 :
						j = (digit[3] * 16) + 2;
						break;
						case 3 :
						j = (digit[4] * 16) + 3;
					}
				}
				else if (t == 4 || t == 5 || t == 6 || t == 7) {
					switch (i) {
						case 0 :
						j = (digit[0] * 16) + 0;
						break;
						case 1 :
						j = (digit[1] * 16) + 1;
						break;
						case 2 :
						j = (digit[2] * 16) + 2;
						break;
						case 3 :
						j = (digit[3] * 16) + 3;
					}
				}
			k = k - 8;
			}
			else {
				j = (digit[i+2] * 16) + i;	// Display HH:MM
			}
			portb = j;
			if (i != 4) {				// Display Dots
				pause(4);
				portb = 0xff;
				}
				else
				{
				tsec = ssec / 4;
				if (tsec > 521) {
					tsec = tsec - 391;
				}
				else {
					tsec = 521 - tsec;
				}
				for ( j = 1 ; j < tsec ; j++) {
						}
				portb = 0xff;
				for ( j = 1 ; j < (1042 - tsec) ; j++) {
						}
				}

//  桁上がりチェック

			if (sinc !=0) {
				sinc = 0;
				digit[0]++;
				if (digit[0] > 9) {
					digit[0] = 0;
					digit[1]++;
				}
				if (digit[1] > 5) {
					digit[1] = 0;
					digit[2]++;
				}
				if (digit[2] > 9) {
					digit[2] = 0;
					digit[3]++;
				}
				if (digit[3] > 5) {
					digit[3] = 0;
					digit[4]++;
				}
				if (digit[4] > 9) {
					digit[4] = 0;
					digit[5]++;
				}
				if ((digit[5] > 1) && (digit[4] > 3)) {
					digit[4] = 0;
					digit[5] = 0;
				}
			}

//  キーチェック
			switch(k) {
				case 3 :
				digit[0] = 0;
				digit[1] = 0;
				break;
				case 5 :
				ksec++;
				if (ksec > 100) {
					ksec = 0;
					digit[2]++;
					if (digit[2] > 9) {
						digit[2] = 0;
						digit[3]++;
					}
					if (digit[3] > 5) {
						digit[3] = 0;
					}
				}
				break;
				case 6:
				ksec++;
				if (ksec > 100) {
					ksec = 0;
					digit[4]++;
					if (digit[4] > 9) {
						digit[4] = 0;
						digit[5]++;
					}
					if ((digit[5] > 1) && (digit[4] > 3)) {
						digit[4] = 0;
						digit[5] = 0;
					}
				}
				break;
			}
		}
	}
}