xtest11_4.c

AT91sam7s 256 B/D example

/* ========================================================================== */
/*	  Xtest11_4.c : Multiple Interrupt Program(RTT & TC0 interrupt)       */
/* ========================================================================== */
/*			  Designed and programmed by Duck-Yong Yoon in 2007.  */

#include "AT91SAM7S256.h"
#include "lib_AT91SAM7S256.h"
#include "OK7S256ads.h"

volatile unsigned int RTT_flag=0;		// RTT interrupt flag
volatile unsigned int TC0_flag=0;		// TC0 interrupt flag

void RTT_ISR(void)				/* RTT interrupt service routine */
{
  if(AT91F_RTTGetStatus(AT91C_BASE_RTTC) & 0x0002) // RTT RTTINC interrupt ?
    { RTT_flag ^= 0x01;				// toggle RTT_flag(2Hz/2 = 1Hz)
      if(RTT_flag == 1)				// if RTT_flag=1, LED1 on
        LED_on(LED1);
      else					// if RTT_flag=0, LED1 off
        LED_off(LED1);
    }
}

void TC0_ISR(void)				/* TC0 interrupt service routine */
{
  if(*AT91C_TC0_SR & 0x0010)			// TC0 CPCS interrupt ?
    { TC0_flag ^= 0x01;				// toggle TC0_flag(6Hz/2 = 3Hz)
     if(TC0_flag == 1)				// if TC0_flag=1, LED2 on
       LED_on(LED2);
     else					// if TC0_flag=0, LED2 off
       LED_off(LED2);
    }
}

int main(void)
{
  MCU_initialize();				// initialize AT91SAM7S256 & kit
  Delay_ms(50);					// wait for system stabilization
  LCD_initialize();				// initialize text LCD module

  LCD_string(0x80, "RTT(LED1) = 2 Hz");		// display title
  LCD_string(0xC0, "TC0(LED2) = 6 Hz");
  Beep();

  LED_off(LED2|LED1);				// LED2~LED1 off

  AT91F_RTTC_CfgPMC();				// initialize RTT
  AT91F_RTTRestart(AT91C_BASE_RTTC);		// clear and restart RTT
  AT91F_RTTSetPrescaler(AT91C_BASE_RTTC,16384);	// 32.768kHz/16384 = 2Hz

  AT91F_RTTSetRttIncINT(AT91C_BASE_RTTC);	// initialize RTT interrupt
  AT91F_AIC_ConfigureIt(AT91C_BASE_AIC,AT91C_ID_SYS,7,1,RTT_ISR);
  AT91F_AIC_EnableIt(AT91C_BASE_AIC,AT91C_ID_SYS);

  AT91F_TC0_CfgPMC();				// initialize TC0
  *AT91C_TC0_CMR = 0x8989C402;			// TC0 Channel Control Register
  *AT91C_TC0_CCR = 0x0005;			// TC0 clock enable and start
  *AT91C_TC0_RA = 10000;			// set TC0 register
  *AT91C_TC0_RB = 20000;
  *AT91C_TC0_RC = 62500;			// (48MHz/128/62500 = 6Hz)

  AT91F_TC_InterruptEnable(AT91C_BASE_TC0,AT91C_TC_CPCS); // initialize TC0 interrupt
  AT91F_AIC_ConfigureIt(AT91C_BASE_AIC,AT91C_ID_TC0,7,1,TC0_ISR);
  AT91F_AIC_EnableIt(AT91C_BASE_AIC,AT91C_ID_TC0);

  while(1);					// wait for interrupts
}