Information about low level digitalwrite and digitalread operations

[ewp]

My understanding is that GPIOs are split into multiple ‘ports’. Each port has 32 GPIOs. So if you wish to (say) control the LED on GPIOC24 you would use GPIO2 base address.

@ewp

  #define GPIO2 0x03022000
  #define GPIO_SWPORTA_DR 0x000
  #define GPIO_SWPORTA_DDR 0x004

  *(uint32_t*)(GPIO2|GPIO_SWPORTA_DDR) = 1 << 24;
  for (i = 0; i < 5; i++)
  {
    *(uint32_t*)(GPIO2|GPIO_SWPORTA_DR) = 1 << 24;
    mdelay(100);
    *(uint32_t*)(GPIO2|GPIO_SWPORTA_DR) = 0;
    mdelay(100);
  }

The above example blinks the on-board LED 5 times.