Subversion Repositories hf-risc

/*
C0 = 16.35	
C#0 = 17.32
DO = 18.35
D#O = 19.45
EO = 20.60
F0 = 21.83
F#0 = 23.12
G0 = 24.50
G#O = 25.96
A0 = 27.50
A#0 = 29.14
BO = 30.87
 
C1 = 32.70
C#1 = 34.65
D1 = 36.71
D#1 = 38.89
E1 = 41.20
F1 = 43.65
F#1 = 46.25
G1 = 49.00
G#1 = 51.91
A1 = 55.00
A#1 = 58.27
B1 = 61.74
 
C2 = 65.41
C#2 = 69.30
D2 = 73.42
D#2 = 77.78
E2 = 82.41
F2 = 87.31
F#2 = 92.50
G2 = 98.00
G#2 = 103.83
A2 = 110.00
A#2 = 116.54
B2 = 123.47
 
C3 = 130.81
C#3 = 138.59
D3 = 146.83
D#3 = 155.56
E3 = 164.81
F3 = 174.61
F#3 = 185.00
G3 = 196.00
G#3 = 207.65
A3 = 220.00
A#3 = 233.08
B3 = 246.94
 
C4 = 261.63
C#4 = 277.18
D4 = 293.66
D#4 = 311.13
E4 = 329.63
F4 = 349.23
F#4 = 369.99
G4 = 392.00
G#4 = 415.30
A4 = 440.00
A#4 = 466.16
B4 = 493.88
 
C5 = 523.25
C#5 = 554.37
D5 = 587.33
D#5 = 622.25
E5 = 659.26
F5 = 698.46
F#5 = 739.99
G5 = 783.99
G#5 = 830.61
A5 = 880.00
A#5 = 932.33
B5 = 987.77
 
C6 = 1046.50
C#6 = 1108.73
D6 = 1174.66
D#6 = 1244.51
E6 = 1318.51
F6 = 1396.91
F#6 = 1479.98
G6 = 1567.98
G#6 = 1661.22
A6 = 1760.00
A#6 = 1864.66
B6 = 1975.53
 
C7 = 2093.00
C#7 = 2217.46
D7 = 2349.32
D#7 = 2489.02
E7 = 2637.02
F7 = 2793.83
F#7 = 2959.96
G7 = 3135.96
G#7 = 3322.44
A7 = 3520.00
A#7 = 3729.31
B7 = 3951.07
*/
 
#include <hf-risc.h>
 
#define BUZZER_PIN	0x08
 
volatile int32_t freq = 1, extio_out;
 
void compare_handler(void){
	COMPARE = COUNTER + (CPU_SPEED / freq);
	extio_out ^= BUZZER_PIN;
	EXTIO_OUT = extio_out;
}
 
int main(void){
	extio_out = 0;
	EXTIO_OUT = extio_out;
 
	// register counter compare interrupt
	interrupt_register(IRQ_COMPARE, compare_handler);
 
	// initialize compare registers, clear compare irqs
	COMPARE = COUNTER + (CPU_SPEED/1000);
 
	// set interrupt mask (unmask peripheral interrupts)
	IRQ_MASK = IRQ_COMPARE;
 
	// global interrupts enable
	IRQ_STATUS = 1;
 
 
	for(;;){
		// play a chromatic scale from C4 to B4
		freq = 262;	delay_ms(250);
		freq = 277;	delay_ms(250);
		freq = 294;	delay_ms(250);
		freq = 311;	delay_ms(250);
		freq = 330;	delay_ms(250);
		freq = 349;	delay_ms(250);
		freq = 370;	delay_ms(250);
		freq = 392;	delay_ms(250);
		freq = 415;	delay_ms(250);
		freq = 440;	delay_ms(250);
		freq = 466;	delay_ms(250);
		freq = 494;	delay_ms(250);
 
		// pause for 1 s
		freq = 1;	delay_ms(1000);
	}
}