Short delays are required while switch debouncing, controlling LCDs, blinking LEDs, etc. The Delay module provides functions to generate short delays. The Delay functions are declared in delay.h. The following example blinks the led every 500ms.

Blink LED. 

#include <delay.h>
#include <board.h>

int main()
{
        board_init();
        delay_init();

        gpio_init();
        gpio_enable_pin(LED1_GPIO);
        gpio_direction_output(LED1_GPIO, OFF);

        while (1) {
                mdelay(250);
                gpio_set_pin(LED1_GPIO, 0);
                mdelay(250);
                gpio_set_pin(LED1_GPIO, 1);
        }
}