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IRQ Not Firing

le Ben S.

Hello,

I am writing an I2C master transmitter object. The problem I am having is that the IRQ Handler for I2C1 is not firing. According to the manual, it should fire after the start condition is sent and the status register is 0x08. When I step through the code with the debugger, the status code is 0x08. I am using an MCB1700 development board. Why is it not firing? Did I not configure something properly? For tests, All I am doing is toggling an LED on when the interrupt fires. Once I solve this problem, I will write the rest of the code.

#include <stdio.h>
#include <LPC17XX.h>
#include "GPIO1Output.h"

GPIO1Output out(P1_28);

__irq void I2C1_IRQHandler(void)
{
        if (LPC_I2C1->I2STAT == 0x08)
        {
             out.Set();
        }
}

int main(void)
{
        // Initialize I2C.
        LPC_PINCON->PINSEL0 = 0x0F;
        LPC_PINCON->PINMODE_OD0 = 0x03;

        NVIC_EnableIRQ(I2C1_IRQn);
        LPC_I2C1->I2CONSET = 0x40;

        LPC_I2C1->I2CONSET = 0x20;
        int status = LPC_I2C1->I2STAT;
}

Parents
  • 0 in reply to le Ben S.

    No, C++ does not cause weak references to interrupt handlers.

    But C++ uses name mangling, which means the external name the linker sees contains extra characters encoding the returned data type, and the parameter list.

    So a C++ file with a function void hello(void) will not let the linker see a function "hello". You don't need to use the braces to wrap. Standard C++ documentation tells you that you can specifiy directly for the function that it should use the C calling convention and have C bindings.

Reply
  • 0 in reply to le Ben S.

    No, C++ does not cause weak references to interrupt handlers.

    But C++ uses name mangling, which means the external name the linker sees contains extra characters encoding the returned data type, and the parameter list.

    So a C++ file with a function void hello(void) will not let the linker see a function "hello". You don't need to use the braces to wrap. Standard C++ documentation tells you that you can specifiy directly for the function that it should use the C calling convention and have C bindings.

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