Blink a LED

gistfile1.asm

	_replace DDRB, 0x04
	_replace PORTB, 0x05
	_replace LEDP, 5
	_replace SPH, 0x3e
	_replace SPL, 0x3d
	_replace RAMEND_HI, 0x04
	_replace RAMEND_LO, 0xff

; Rest and Interrupt table for ATmega168
	_loc 0
	jmp RESET		; Reset Handler
	jmp IgnoreINT		; IRQ0 Handler
	jmp IgnoreINT		; IRQ1 Handler
	jmp IgnoreINT		; PCINT0 Handler
	jmp IgnoreINT		; PCINT1 Handler
	jmp IgnoreINT		; PCINT2 Handler
	jmp IgnoreINT		; Watchdog Timer
	jmp IgnoreINT		; Timer2 Compare
	jmp IgnoreINT		; Timer2 Compare
	jmp IgnoreINT		; Timer2 Overflow Handler
	jmp IgnoreINT		; Timer1 Capture Handler
	jmp IgnoreINT		; Timer1 Compare A Handler
	jmp IgnoreINT		; Timer1 Compare B Handler
	jmp IgnoreINT		; Timer1 Overflow Handler
	jmp IgnoreINT		; Timer0 Compare A Handler
	jmp IgnoreINT		; Timer0 Compare B Handler
	jmp IgnoreINT		; Timer0 Overflow Handler
	jmp IgnoreINT		; SPI Transfer Complete Handler
	jmp IgnoreINT		; USART, RX Complete Handler
	jmp IgnoreINT		; USART, UDR Empty Handler
	jmp IgnoreINT		; USART, TX Complete Handler
	jmp IgnoreINT		; ADC Conversion Complete Handler
	jmp IgnoreINT		; EEPROM Ready Handler
	jmp IgnoreINT		; Analog Comparator Handler
	jmp IgnoreINT		; 2-wire Serial Interface Handler
	jmp IgnoreINT		; Store Program Memory Ready Handler

IgnoreINT:	reti

longDelay:
	clr   R1
	clr   R2		;R2 used as delay 3d count
delay_1:
	dec   R2
	brne  delay_1            
	dec   R1
	brne  delay_1           
	dec   R19
	brne  delay_1		; delay master count
	ret                     

RESET:
	ldi   r16, RAMEND_HI	; Main program start
	out   SPH,r16		;Set Stack Pointer to top of RAM
	ldi   r16, RAMEND_LO
	out   SPL,r16
	cli
	sbi   DDRB, LEDP		;connect LED to PORTD pin 5, aka D13

flash:	sbi   PORTB, LEDP	;LED on
	ldi   R19, 10		;X sec delay           
	rcall longDelay             
	cbi   PORTB, LEDP	;LED off            
	ldi   R19, 10		;X sec delay
	rcall longDelay
	rjmp  flash		;another run