#define F_CPU 1200000ul
 #include <avr/io.h>
 #include <util/delay.h>

int main(void)
{
    DDRB |= (1<<PB0);
    /* Replace with your application code */
    while (1)
    {
        PORTB |= (1<<PB0);
        _delay_us(100);
        PORTB &= ~(1<<PB0);
        _delay_us(100);
    }
}




-----------------------------------
AVR DISASSEMBLER LISTING
Address Opcode  Instruction
-----------------------------------
000000  C009    L5: RJMP L1
000001  C00E        RJMP L2
000002  C00D        RJMP L2
000003  C00C        RJMP L2
000004  C00B        RJMP L2
000005  C00A        RJMP L2
000006  C009        RJMP L2
000007  C008        RJMP L2
000008  C007        RJMP L2
000009  C006        RJMP L2
00000A  2411    L1: CLR R1
00000B  BE1F        OUT SREG,R1
00000C  E9CF        LDI YL,$9F
00000D  BFCD        OUT SPL,YL
00000E  D002        RCALL L3
00000F  C00D        RJMP L4
000010  CFEF    L2: RJMP L5
000011  9AB8    L3: SBI DDRB,0
000012  9AC0    L8: SBI PORTB,0
000013  E288        LDI R24,$28
000014  958A    L6: DEC R24
000015  F7F1        BRNE L6
000016  0000        NOP
000017  98C0        CBI PORTB,0
000018  E288        LDI R24,$28
000019  958A    L7: DEC R24
00001A  F7F1        BRNE L7
00001B  0000        NOP
00001C  CFF5        RJMP L8
00001D  94F8    L4: BCLR 7
00001E  CFFF    L9: RJMP L9