KL02 Port A No Control

[brianpetty]

I am new the Kinetis world and I am having a head scratching problem.

I cannot seem to gain total control over the Port Control Registers for port A. I was having a problem setting the appropriate mux setting on individual pins then I learned I needed to enable the gate to clock the port which I did and that allowed me to set the mux functions on the pins. However, I also attempted to set the IRQC in the port control register (for some pin in port A) and will not work. Never sets the IRQC value. But the same construct works on any port B pin. I set the IRQC and the interrupt if enable is serviced. I check the SIM regs and both port A and B clocks are enabled. What is causing port A not to work?

I have scanned the documentation several times with nothing pointing me to a smoking gun.

Please help, seems like something simple but I cannot find it!

Many thanks,

B-rian

[brianpetty]

Here is my gpio_init function...

void gpio_init(void)

{

    // enable clock for gpio ports a and b

    SIM_SCGC5 |= SIM_SCGC5_PORTA_MASK + SIM_SCGC5_PORTB_MASK;

    // select gpio as pin functionality

    gpio_PTB_PCR1 |= PORT_PCR_MUX(PIN_FUNC_ALT1);    // unused

    gpio_PTB_PCR2 |= PORT_PCR_MUX(PIN_FUNC_ALT1);    // adc_pdrst_n

    gpio_PTB_PCR5 |= PORT_PCR_MUX(PIN_FUNC_ALT1);    // unused

    gpio_PTA_PCR6 |= PORT_PCR_MUX(PIN_FUNC_ALT1);    // adc_drdy_n/spi_0_miso

    // configure port b pins and clear output states of port b pins

    gpio_PTB_PDDR |= gpio_PTB_PDRST_N + gpio_PTB_1_UNUSED + gpio_PTB_5_UNUSED;

    gpio_PTB_PCOR |= gpio_PTB_PDRST_N + gpio_PTB_1_UNUSED + gpio_PTB_5_UNUSED;

    // testing...

    gpio_PTB_PCR2 |= PORT_PCR_IRQC(PIN_IRQC_8); -- this works...

    gpio_PTA_PCR6 |= PORT_PCR_IRQC(PIN_IRQC_8); -- this does NOT! Why?

    // configure port a pins

    gpio_PTA_PDDR |= gpio_PTA_DRDY_N + gpio_PTA_5_UNUSED + gpio_PTA_7_UNUSED;

    gpio_PTA_PCOR |= gpio_PTA_5_UNUSED + gpio_PTA_7_UNUSED;

    return;

}

[Jorge_Gonzalez · Accepted solution]

Hello Brian Petty:

Some bits of the Port Control Register are read only if the pin does not support the corresponding feature. For example see the note for IRQC in the Reference Manual:

Then in the chapter Port Control and interrupt summary you can find this table:

You can see how PTA6 is not one of the pins supporting interrupts.

I hope this helps to clarify.

Best Regards!
Jorge Gonzalez

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