#include <inttypes.h>
#include <avr/io.h>
#include <avr/interrupt.h>
#include <avr/signal.h>
#include <avr/delay.h>

#  define YCOE PA7 //pin 2 JP3 ATmega16 pin 33 connect thru 1K resistor
#  define YRST PA5 //pin 3 JP3 ATmega16 pin 35 connect thru 1K resistor
#  define SDIN PD3 //pin 4 JP3 ATmega16 pin 17 connect thru 1K resistor
#  define SYNC PD6 //pin 5 JP3 ATmega16 pin 20 connect thru 1K resistor
#  define SCLK PD4 //pin 7 JP3 ATmega16 pin 18 connect thru 1K resistor
#  define IRQ  PD2 //pin 8 JP3 ATmega16 pin 16 connect directly
#  define MPWM PD5 //pin 9 JP3 ATmega16 pin 19 connect thru 1K resistor 


volatile uint8_t Yflag, x, y;

// function actually writes data to an address in the Yamaha sound chip.
// sends 8-bits to the Yamaha sound chip by controlling the SCLK, SDIN wires
void
send_fm8 (uint8_t shift) 
{
	return;
}

// function that writes data to an address in the Yamaha sound chip.
// processes the addr/data and should call send_fm8(uint8_t shift)
// to send bits, _must_ configure SYNC, SCLK, SDIN wires appropriately
// for beginning and end of transmission
void
send_fm (uint8_t addr, uint16_t data) 
{	

        return;
}

void
init_fm (void) 
{
// setup I/O
	DDRD = 0x78;
	DDRA = 0xA0;
	PORTD = 0; // SDIN, SYNC, and SCLK = 0
// reset both chips
// we use delays to ensure proper timing for Yamaha operations
	PORTA = 0x00; // both reset (low)
		//wait (100 x 4) cycles = wait 400 cycles = >100 YCLK cycles, ~55 usec.
		_delay_loop_2(100);
// start oscillator
	PORTA = 0x80;
		//wait (100 x 4) cycles = wait 400 cycles = >100 YCLK cycles, ~55 usec.
		_delay_loop_2(100);
// reset fm chip
	PORTA = 0xA0;
		_delay_loop_2(100);	
// set the clock divider CLKSEL ( $33 = 0; default reset) $39 = 64;
	send_fm(0x33,0);
	send_fm(0x39,0x40);
		_delay_loop_2(30000);
// set power management AP1 = 0 $38 = $1C
	send_fm(0x38,0x1C);
		_delay_loop_2(30000);	
		_delay_loop_2(30000);	
		_delay_loop_2(30000);	
// set power management AP1,AP2 = 0$38 = $18
	send_fm(0x38,0x18);
		_delay_loop_2(1000);	
// set power management all on $38 = $00
	send_fm(0x38,0x00);
		_delay_loop_2(30000);	
		
// set timbre data $10-2F  
	send_fm(0x10,0xc223);	// modulator 1
	send_fm(0x11,0x0bf0);
	send_fm(0x12,0xC223);	// carrier 1
	send_fm(0x13,0x0800);
// set timbre allotment data $30 = 0 all voices modulator 1 carrier 1
	send_fm(0x30,0);
// set tempo data $31 = 72 (120 beats/min)
	send_fm(0x31,31);
// set volumes $35, $36
	send_fm(0x35,0x15);
	send_fm(0x36,0x15);
//------------------end of initialization--------------------------
}


// function loads up a sample birdsong into the Yamaha sound
// chips FIFO and begins playing
void
send_birdcall(void)
{
// write notes and a rest to FIFO

// bbwa
        send_fm(0,0xc847);  //1100 1000 0100 0111  bbwa
        send_fm(0,0xbc60);  //1011 1100 0110 0000
        send_fm(0,0xb42b);  //1011 0100 0010 1011
        send_fm(0,0xdc33);  //1101 0100 0010 1011
        send_fm(0,0xcc33);  //1100 1100 0011 0011
        send_fm(0,0xc874);  //1100 1000 0111 0100
        send_fm(0,0xc411);  //1100 0100 0001 0001
        send_fm(0,0xbc12);  //1011 1100 0001 0010
        send_fm(0,0xac11);  //1010 1100 0001 0001
        send_fm(0,0xc412);  //1100 0100 0001 0010
        send_fm(0,0xd411);  //1101 0100 0001 0001
        send_fm(0,0xdc12);  //1101 1100 0001 0010
        send_fm(0,0xd811);  //1101 1000 0001 0001
        send_fm(0,0xdc12);  //1101 1100 0001 0010
        send_fm(0,0xd823);  //1101 1000 0010 1011
        send_fm(0,0xd43c);  //1101 0100 0011 1100
        send_fm(0,0xcc47);  //1100 1100 0100 0111
        send_fm(0,0xbc11);  //1011 1100 0001 0001
        send_fm(0,0xf411);  //1111 0100 0001 0001
        send_fm(0,0xe812);  //1110 1000 0001 0010
        send_fm(0,0xf412);  //1111 0100 0001 0010
        send_fm(0,0xe433);  //1110 0100 0011 0011
        send_fm(0,0xdc12);  //1101 1100 0001 0010
        send_fm(0,0xe469);  //1110 0100 0110 1001
        send_fm(0,0xe812);  //1110 1000 0001 0010
        send_fm(0,0xe423);  //1110 0100 0010 1011
        send_fm(0,0xe811);  //1110 1000 0001 0001
        send_fm(0,0xe411);  //1110 0100 0001 0001
        send_fm(0,0xe812);  //1110 1000 0001 0010
        send_fm(0,0xe411);  //1110 0100 0001 0001

// $00 = $3000 a rest
	send_fm(0,0x3000);
// set up interrupt
	send_fm(0x34,0x0021);
// start FM $32 = 1
	send_fm(0x32,1);
}

int
main (void)
{
  // initialize interrupts
  
  init_fm(); // initialize Yamaha

  sei();
  
  // send an initial birdcall to get things started
  send_birdcall();
  
  /* loop forever, the interrupts are doing the rest */
  for (;;){ 
    // send another birdcall only if we've been interrupted by the Yamaha chip
    if( /* TODO */   ){
      // clear interrupt
      send_fm(0x34,0x0);
      
      send_birdcall();
    }
  }

  // never reached
  return (0);
}