ATMEGA128, CodeVisonAVR, TIMER, timer_overflow_intr_1ms

ATMEGA128, CodeVisonAVR, TIMER, timer_overflow_intr_1ms

0. 참고 자료

• http://miobot.tistory.com/26
• http://wjs890204.tistory.com/754
  
• http://ww1.microchip.com/downloads/en/DeviceDoc/doc2467.pdf

1. 모듈

2. HW 구성

3. Ports > Bit0 out

LED Port

4. Timers > Timer0

• Clock Source : System Clock
• Clock Value : 16000 kHz
• Mode : Normal Mode=0xFF
• Overflow Interrupt : check
• Timer Value : 6
• Timer Count가 0~ 249에서 overflow를 발생하기 위함
  

5. SW 구성

#include <mega128.h> // Timer 0 overflow interrupt service routine interrupt [TIM0_OVF] void timer0_ovf_isr(void) { // Reinitialize Timer 0 value TCNT0=0x06; // Place your code here     // 16MHz / 64 = 250000Hz = 0.004ms = 4us     // 0.004ms * 250 = 1ms     PORTA ^= 0x01; } // Declare your global variables here void main(void) { // Declare your local variables here // Input/Output Ports initialization // Port A initialization // Func7=In Func6=In Func5=In Func4=In Func3=In Func2=In Func1=In Func0=Out // State7=T State6=T State5=T State4=T State3=T State2=T State1=T State0=0 PORTA=0x00; DDRA=0x01; //TCCR0=0x01; TCCR0 = // 64 prescaler (0 << FOC0)  | (0 << WGM00) | (0 << COM01) | (0 << COM00) | (0 << WGM01) | (1 << CS02)  | (0 << CS01)  | (0 << CS00); TCNT0=0x06; OCR0=0x00; // Timer(s)/Counter(s) Interrupt(s) initialization TIMSK=0x01; ETIMSK=0x00; // Global enable interrupts #asm("sei") while (1)       {       // Place your code here       } }

6. 소스

• https://github.com/sglee0223/atmega128/tree/master/timer_overflow_intr_1ms
  

7. 결과

1ms 마다 LED Port가 동작하는 것을 확인할 수 있습니다.