GPIO Outputs

seanmccartan — Sat, 23 May 2020 17:54:13 GMT

Micro: MKV10Z32VLF7

IDE: MCUXpresso

I am trying to configure two pins on this micro to be digital outputs: PTC6 (pin 39) & PTC7 (pin 40). Code as follows:

gpio_pin_config_t PortC6 = {kGPIO_DigitalOutput,1}; // LED0, startup as HI

gpio_pin_config_t PortC7 = {kGPIO_DigitalOutput,1}; // LED1, startup as HI

void BOARD_InitPins(void)
{
CLOCK_EnableClock(kCLOCK_PortC);

PORT_SetPinMux(PORTC, 6U, kPORT_MuxAsGpio);

PORT_SetPinMux(PORTC, 7U, kPORT_MuxAsGpio);

GPIO_PinInit(GPIOC,6U,&PortC6);

GPIO_PinInit(GPIOC,7U,&PortC7);

}

After running the above code, neither of the pins are high.

I read back the following registers:

GPIOC_PDIR: 0x0 - Incorrect, read only register, should be 0xC0

GPIOC_PDDR: 0xC0 - Correct (both pins assigned as outputs)

GPIOC_PDOR: 0xC0 - Correct (both pins assigned level '1')

A value of "0" in the "GPIOC_PDIR" register indicating:"0 Pin logic level is logic 0, or is not configured for use by digital function."

What this is telling me is that I cannot assign these two pins as digital logic. Surely this is not correct? What am I missing here?

Regards,

Sean

Re: GPIO Outputs

seanmccartan — Sun, 24 May 2020 07:41:09 GMT

I found the answer:"PTC6 and PTC7 are true open drain pins. These pins cannot drive a logic one without a pull-up resistor."