ZYNQ essays --AXI_GPIO bare metal design

1. Hardware platform structures
in Block Design was added and AXI_GPIO module ZYNQ7 Processing System, double AXI_GPIO set to output the drive external IO device (e.g., LED). Good build the system configuration as shown below:

2. Software design SDK
SDK software design can refer to the official design documents, the main API function has,

• int XGpio_Initialize(XGpio * InstancePtr,u16 DeviceId)
• void XGpio_SetDataDirection(XGpio * InstancePtr,unsigned Channel,u32 DirectionMask)
• void XGpio_DiscreteWrite(XGpio * InstancePtr,unsigned Channel,u32 Data)
• u32 XGpio_DiscreteRead(XGpio * InstancePtr,unsigned Channel)
• void XGpio_DiscreteClear(XGpio * InstancePtr,unsigned Channel,u32 Mask)

Specific code as follows,

int main(void)
{
    int Status;
    volatile int Delay;

    /* Initialize the GPIO driver */
    Status = XGpio_Initialize(&Gpio, GPIO_EXAMPLE_DEVICE_ID);
    if (Status != XST_SUCCESS) {
        xil_printf("Gpio Initialization Failed\r\n");
        return XST_FAILURE;
    }

    /* Set the direction for all signals as inputs except the LED output */
    XGpio_SetDataDirection(&Gpio, LED_CHANNEL, ~LED);

    xil_printf("Gpio Example\r\n");

    /* Loop forever blinking the LED */

    while (1) {
        /* Set the LED to High */
        XGpio_DiscreteWrite(&Gpio, LED_CHANNEL, LED);

        /* Wait a small amount of time so the LED is visible */
        for (Delay = 0; Delay < LED_DELAY; Delay++);

        /* Clear the LED bit */
        XGpio_DiscreteClear(&Gpio, LED_CHANNEL, LED);

        /* Wait a small amount of time so the LED is visible */
        for (Delay = 0; Delay < LED_DELAY; Delay++);
    }

    xil_printf("Successfully ran Gpio Example\r\n");
    return XST_SUCCESS;
}

3. compile and run
download FPGA code to run the software Hardware, in the print terminal GPIO Example, outside LED blinking.