Spi external interrupt code for pic24fj64ga006

[user19]

Hi,

I am trying to get the external interrupt (using external interrupt 3 ) code to work on my pic24fj64ga006. I can see the pin going low but not triggering the interrupt.

Is enabling the interrupt and setting priority enough for the interrupt to work ?


Please find the attached code

#include <p24FJ64GA006.h>
#include "p24fxxxx.h"
#include "xc.h"

#ifdef __PIC24FJ64GA006__ //Defined by MPLAB when using 24FJ256GB110 device
 // JTAG/Code Protect/Write Protect/Clip-on Emulation mode
 // Watchdog Timer/ICD pins select
 _CONFIG1(JTAGEN_OFF & GCP_OFF & GWRP_OFF & COE_OFF & FWDTEN_OFF & ICS_PGx1) 
 // Disable CLK switch and CLK monitor, OSCO or Fosc/2, HS oscillator,
 // Primary oscillator
 _CONFIG2(FCKSM_CSDCMD & OSCIOFNC_OFF & POSCMOD_HS & FNOSC_PRIPLL)
#endif

// RB6 as SS for SPI slave MCU
#define SPI_SS_TRIS TRISBbits.TRISB6
#define SPI_SS_PORT PORTBbits.RB6

unsigned short spiBufT[]={0x02,0x03,0x0d,0}; 
int Counter = 0;

void InitClock()
{
    CLKDIVbits.RCDIV=0;
    while(OSCCONbits.LOCK != 1) {};
}

void SPI2Init(void)
{
    //config SPI1
    SPI2STATbits.SPIEN = 0; // disable SPI port
    SPI2STATbits.SPISIDL = 0; // Continue module operation in Idle mode
    
    SPI2BUF = 0; // clear SPI buffer
    
    IFS2bits.SPI2IF = 0; // clear interrupt flag
    IEC2bits.SPI2IE = 0; // disable interrupt
    
    SPI2CON1bits.DISSCK = 0; // Internal SPIx clock is enabled
    SPI2CON1bits.DISSDO = 0; // SDOx pin is controlled by the module
    SPI2CON1bits.MODE16 = 0; // set in 16-bit mode, clear in 8-bit mode
    SPI2CON1bits.SMP = 0; // Input data sampled at middle of data output time
    SPI2CON1bits.CKP = 0; // CKP and CKE is subject to change ...
    SPI2CON1bits.CKE = 0; // ... based on your communication mode.
    SPI2CON1bits.MSTEN = 1; // 1 = Master mode; 0 = Slave mode
    SPI2CON1bits.SPRE = 4; // Secondary Prescaler = 4:1
    SPI2CON1bits.PPRE = 2; // Primary Prescaler = 4:1
 
    SPI2CON2 = 0; // non-framed mode
    
    SPI_SS_PORT = 1; // ALL SPI_SS_PORT PINS ARE CLEARED
    SPI_SS_TRIS = 0; // set SS as output -RB6
 
    SPI2STATbits.SPIEN = 1; // enable SPI port, clear status
}

unsigned short writeSPI2( unsigned short data )
{
    
    SPI2BUF = data; 
    while(!SPI2STATbits.SPIRBF); // wait for transfer to complete
    return SPI2BUF; // read the received value
}

int main (void)
{
    
 unsigned short i;
 InitClock();
  
 SPI2Init();
 SPI_SS_PORT = 0;
    
     
    //Enable interrupts...
            
    
    //INTCON1bits.NSTDIS = 1; // Disable nested interrupts
    INTCON2bits.INT3EP = 1; // Interrupt on positive edge of External Interrupt 3
    IPC13bits.INT3IP = 001; // Priority level
    //IFS3bits.INT3IF = 1; // Interrupt req flag status 
    IEC3bits.INT3IE = 1; // Enable interrupt
    
        
    while(1)
    {
        
    }
    
    SPI_SS_PORT = 1;
 return 0;
}

void __attribute__((__interrupt__, no_auto_psv)) _INT3Interrupt(void)
{
    //clear interrupt flag
    IFS3bits.INT3IF = 0; 
    int i;
    // SPI Read...
    Counter++;
    
}

Thanks & Regards

 

[barry]

I think you also need to enable the spi interrupt with IEC3bits.SPI1IE=1.