//-----------------------------------------------------------
//              Nixie Clock Kennel Method
//		2003/02/28
//              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, j, sinc;
long ssec, psec, ksec;

//*****************************
// 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++;
	psec++;
	if (psec >= 6250) {
		psec = 0;
		}
	if (ssec >= 3125) {
		ssec = 0;
		sinc = 1;
		}
}

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

//  初期化

	ssec = 0;
	psec = 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 < 6 ; i++) {
			j = (digit[i] * 16) + i;

//  DPコントロールによる振り子

			switch(i){
				case 0 :
				if (((5250 > psec) && (4125 < psec)) || ((4875 > psec) && (3750 < psec))) {
		 		j = j + 8;
				}
				break;
				case 1 :
				if (((4000 > psec) && (3250 < psec)) || ((5750 > psec) && (5000 < psec))) {
		 		j = j + 8;
				}
				break;
				case 2 :
				if (((3500 > psec) && (3250 < psec)) || ((6000 > psec) && (5875 < psec)) || ((3125 > psec) && (2750 < psec)) || ((5750 > psec) && (5500 < psec))) {
		 		j = j + 8;
				}
				break;
				case 3 :
				if ((( 375 > psec) && (   0 < psec)) || ((3125 > psec) && (2750 < psec)) || ((2625 > psec) && (2375 < psec)) || ((6250 > psec) && (5875 < psec))) {
		 		j = j + 8;
				}
				break;
				case 4 :
				if ((( 875 > psec) && ( 125 < psec)) || ((2625 > psec) && (1875 < psec))) {
		 		j = j + 8;
				}
				break;
				case 5 :
				if (((2125 > psec) && (1000 < psec)) || ((1750 > psec) && ( 625 < psec))) {
		 		j = j + 8;
				}
				break;
			}
			portb = j;
			pause(4);
			portb = 0xff;

//  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
			j = porta;
			switch(j) {
				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;
			}
		}
	}
}