zomg asm framework

avr/noiseplug.s

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+.global __vectors
+
+SREG = 0x3F
+CCP = 0x3C
+SMCR = 0x3A
+CLKPSR = 0x36
+TCCR0A = 0x2E
+TCCR0B = 0x2D
+TCCR0C = 0x2C
+TIMSK0 = 0x2B
+TIFR0 = 0x2A
+OCR0AL = 0x26
+PUEB = 0x03
+PORTB = 0x02
+DDRB = 0x01
+PINB = 0x00
+
+.section .bss
+
+	.comm int_ctr, 1
+	.comm i, 3
+	.comm lead1, 4
+	.comm lead2, 4
+	.comm lead3, 4
+	.comm bassosc, 2
+	.comm bassflange, 2
+	.comm arposc, 2
+	; leaves 10 bytes for stack
+
+.section .text
+
+__vectors:
+	clr r16
+	ldi r17, 0xD8
+	out PUEB, r16
+	rjmp main_cont
+
+	.type	__vector_4, @function
+__vector_4:
+	push r16
+	push r24
+	in r16, SREG
+	lds r24,int_ctr
+	subi r24,lo8(-(1))
+	andi r24,lo8(3)
+	sts int_ctr,r24
+	out SREG,r16
+	pop r24
+	pop r16
+	reti
+	.size	__vector_4, .-__vector_4
+
+main_cont:
+	out CCP, r17
+	out CLKPSR, r16
+	ldi r17, 5
+	out DDRB, r17
+	ldi r17, 0x81
+	out TCCR0A, r17
+	ldi r17, 0x09
+	out TCCR0B, r17
+	ldi r17, 1
+	out SMCR, r17
+	out TIMSK0, r17
+	sei
+	out TIFR0, r17
+
+mainloop:
+	sleep
+	lds r17, int_ctr
+	tst r17
+	brne mainloop
+
+	sbi PORTB, 2
+
+	lds r17, i
+	lds r18, i+1
+	lds r19, i+2
+
+	subi r19, -1
+	sbci r18, 0
+	sbci r17, 0
+
+	sts i, r17
+	sts i+1, r18
+	sts i+2, r19
+
+	out OCR0AL, r18
+
+	cbi PORTB, 2
+	rjmp mainloop