Sami Elias

Help with interrupts!

Discussion created by Sami Elias on Apr 21, 2012
Latest reply on Apr 22, 2012 by kef

I wrote a simple program that has 2 ISRs, one plays a music note, the other updates time every mS.

The problem that i am having is that when i disable the interrupt that updates the time, the tones are played as expected, however when i enable the time update interrupt, the some of the tones come and go and the program does not function correctly. Can you please help, Thank you

 

#include <hidef.h>      /* common defines and macros */ #include "derivative.h"      /* derivative-specific definitions */ #include <MC9S12C128.h>     /* derivative information */ #include <stdio.h> #include <math.h> ///   FUNCTIONS   /// void initializePorts(void); void Delay(); byte getKey(); byte control(); void play(); ///  GLOBAL VARIABLES   /// volatile int msCount;

volatile int M; ////////////////////////////////////////////////////////

void main() {  volatile byte MODES;  initializePorts();  TSCR1 = 0x80;     //Allows the timer to function  TSCR2 = 1;     //prescaler = 2, clock is at Buss Speed / 2 = 2MHz/2 = 1MHz    TIE_C5I = 1;    TIOS = 0xE0;   //Chanal 7-5 isr act as an output campare with MCU timer //////////////////////////////////////////////////////////////////////////// //          initializing timers and counters..                          /// ///////////////////////////////////////////////////////////////////////////  EnableInterrupts;    for(;:smileywink: {      MODES = control();      if(MODES == 1)       play();       }/* loop forever */ }

///////////////// Timer6 Interrupt Service Routine  ///////////// void interrupt 14 ISR_Timer6(void) {     TC6 = TC6 + M;     //802       TFLG1_C6F = 1;            }

void interrupt 13 ISR_Timer5(void) {    msCount++;    TC5 = TC5 + 1000; // Interrupt again in 1 second, set the next match value for TC5,                      // When Timer chanal 5(TC5) matches the MCU counter, an interrupt occurs.    TFLG1_C5F = 1;    //when TC5 matches MCU timer, a flag is set, this flag must be cleared                      // in order to work interrupt again. Right here, we are clearing the flag                      // set for TC5 by clearing the flag set by TC5                      //TCTL1 regesters connects timers to pins PT

}

 

 

 

void initializePorts() {    DDRA = 0xFF;   // PTA<7:0> - outputs  (LEDs)    DDRB = 0xF0;   // Make PTB<7:4> outputs    DDRM = 0x00;   //Make Portm  inputs    PERM_PERM5;    PERM_PERM4;   return; }

void Delay(int mS){    int j;    int count;    for(j = 0; j < mS; j++){       for(count = 0; count < 300; count++)       ;    }    return; }

byte getKey(){     byte row[4] = {1,2,4,8};     int count = 0;     DDRT = 0x0F;        //port T  is rows, output     DDRP = 0x00;         //portp is coloumns, input     PPSP = 0x0F;      //pull down imput P which is coloumns         for(count = 0; count < 4; count++){         PTT = row[count];         Delay(0);             if(PTP_PTP0 == 1)             return 4*count;           else if(PTP_PTP1 == 1)             return 4*count+1;         else if(PTP_PTP2 == 1)             return 4*count+2;         else if(PTP_PTP3 == 1)             return 4*count+3;     }        return 0XFF; }

/////////////////////////////////////////////////////////////////// //                   PLAY FUCNION                              //// ////////////////////////////////////////////////////////////////// void play() {    byte keybounce;    byte press;    volatile int notes[16] = {1804,1607,1432,1352,1204,1073,1012,0,902,804,716,637,602,536,478,451};    PORTA = 0x11;    TIE_C6I = 1;     while(1)    {      press = getKey();      if(press == 7)         {          TIE_C6I = 0;          TCTL1_OL6 = 0;          return;         }      else if(press == 0xFF)         TCTL1_OL6 =0;      else      {          M = notes[press];          TCTL1_OL6 = 1;          keybounce = press;          while(keybounce == press)             press = getKey();

     }    } }

 

 

/////////////////////////////////////////////////////////////////// //          CONTROL FUNCTION (PLAY, RECORD, PLAYBACK)         //// ////////////////////////////////////////////////////////////////// byte control(){

   byte options;    int blinker = msCount;    PORTA = 0x00;    while(1)    {       if(msCount - blinker > 200)       {          PORTA = ~PORTA;          blinker = msCount;       }    options = getKey();    if(options == 0)       return 1;    else if(options == 1)       return 2;    else if(options == 2)       return 3;     } }

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