How can I write a pulse per second(PPS) signal that comes every 100 ms in C?

Question

I am working on a MTS board in FreeRTOS. Right now I am focused on the GPS module and it has 2 signals. One for waking it up and another one called PPS which is a signal normally at 1 but that goes to 0 every 100ms. I need to write the code in C for this second part.

I have done it this way but I don't think it's correct. I'm not sure if it's super simple ad I am over complicating it or vice versa. Any help would be appreciated.

while(1)
    {
        if((vGPIO1->vFIOPIN &= (1<<18)))  // pps is 1
        {       
        vTaskDelay(100/portTick_PERIOD_MS); // wait for 100ms
        vGPIO1->vFIOCLR &= ~(1<<18);        // after 100 ms goes to 0
        }
    }