//2005.10.21-2008.7.31 tiny2313 “dŽqƒsƒAƒm	koyama@cc.hirosaki-u.ac.jp
#define	Nkey	13
#define	Nc		256
#define	ts		0.00006375
#include <avr/io.h>
#include <avr/interrupt.h>
#include <avr/pgmspace.h>
// ³Œ·”g
prog_uint8_t W[]={0,0,0,0,1,1,1,2,2,3,4,5,5,6,7,9,10,11,12,14,15,17,18,20,21,23,25,27,29,31,33,35,37,40,42,44,47,49,52,54,57,59,62,65,67,70,73,76,79,82,85,88,90,93,97,100,103,106,109,112,115,118,121,124,127,131,134,137,140,143,146,149,152,155,158,162,165,167,170,173,176,179,182,185,188,190,193,196,198,201,203,206,208,211,213,215,218,220,222,224,226,228,230,232,234,235,237,238,240,241,243,244,245,246,248,249,250,250,251,252,253,253,254,254,254,255,255,255,255,255,255,255,254,254,254,253,253,252,251,250,250,249,248,246,245,244,243,241,240,238,237,235,234,232,230,228,226,224,222,220,218,215,213,211,208,206,203,201,198,196,193,190,188,185,182,179,176,173,170,167,165,162,158,155,152,149,146,143,140,137,134,131,128,124,121,118,115,112,109,106,103,100,97,93,90,88,85,82,79,76,73,70,67,65,62,59,57,54,52,49,47,44,42,40,37,35,33,31,29,27,25,23,21,20,18,17,15,14,12,11,10,9,7,6,5,5,4,3,2,2,1,1,1,0,0,0};
uint16_t Xsw[]={
	ts*Nc*523.25*256,	ts*Nc*554.37*256,
	ts*Nc*587.33*256,	ts*Nc*622.25*256,
	ts*Nc*659.26*256,
	ts*Nc*698.46*256,	ts*Nc*739.99*256,
	ts*Nc*783.99*256,	ts*Nc*830.61*256,
	ts*Nc*880.00*256,	ts*Nc*932.33*256,
	ts*Nc*987.77*256,
	ts*Nc*1046.5*256
};
uint16_t	KEY=0xff, KEY0=0xff, KEYon=0, X[Nkey], v, x, E[Nkey];
uint8_t  i, j, g=0, c=0, KEY1=255, KEY2=255, KEY3=255;
SIGNAL(SIG_TIMER1_OVF){						// .125*510=63.75us(@8MHz)
	if(--c==0)	g++;						// 63.75us*256=16.32ms
	v=0;									// U•
	if((i=KEY1)<Nkey && E[i]>=Nc){
		v+=pgm_read_byte(&W[(x=128+(X[i]+=Xsw[i]))>>8]);
		v+=pgm_read_byte(&W[(x+(Nc<<7)-E[i])>>8]);
		if(c==0)	E[i]-=(E[i]>>4);
	}else v+=256;
	if((i=KEY2)<Nkey && E[i]>=Nc){
		v+=pgm_read_byte(&W[(x=128+(X[i]+=Xsw[i]))>>8]);
		v+=pgm_read_byte(&W[(x+(Nc<<7)-E[i])>>8]);
		if(c==0)	E[i]-=(E[i]>>4);
	}else v+=256;
	if((i=KEY3)<Nkey && E[i]>=Nc){
		v+=pgm_read_byte(&W[(x=128+(X[i]+=Xsw[i]))>>8]);
		v+=pgm_read_byte(&W[(x+(Nc<<7)-E[i])>>8]);
		if(c==0)	E[i]-=(E[i]>>4);
	}else v+=256;
	OCR1AL=OCR1BL=v>>3;
}
int main (void){
	PORTB=0xf7;	DDRB=0x18;					// rrroorrr
	PORTD=0x7f;	DDRD=0x00;					// xrrrrrrr
	TCCR1A=0xb1;							// OC1A=!OC1B=0/1 on COM
	TCCR1B=0x01;							// Timer1: 8 bit PhaseCorr PWM,CK/1
	TIMSK=(1<<TOIE1);
	sei();
LOOP:
	if(g){									// 16.32ms
		g--;
		KEY0=KEY;	KEY=(PINB&0x07) | ((PINB&0xe0)>>2) | ((PIND&0x7f)<<6);
		KEYon=KEY0&(~KEY);					// ON‚Ι‚Θ‚Α‚½ƒrƒbƒg‚ͺ1
		for(j=0;j<Nkey;j++)if(KEYon&(1<<j)){// KEY1`KEY3‚Μ3‰Ή
			if(!(j==KEY3||j==KEY2||j==KEY1)){KEY3=KEY2;	KEY2=KEY1;	KEY1=j;}
			E[j]=Nc<<7;
		}
	}
	goto LOOP;
}