Pin Drivers

All applications at some point will need to manipulate the pins on the microcontroller. For each supported microcontroller, the Embedded SDK includes a driver that provides the ability to read, write and configure the pins.

Each driver contains an enumeration of the available ports (typedef PORT) and pins (typedef PIN) for the target controller. Although each MCU has a different set of available pins, the pin drivers provide a consistent method for reading and setting the pin states.

Basic Usage

The code snippet below illustrates how to read and write a single pin.

#include "mcu_pin.h"


void APP_Function(void)
{
    UINT32 state;


    state = PIN_Read(P1_01);        /* Read pin P1.1, either a '0' or '1' */
    PIN_Write(P1_02, state);        /* Set pin P1.2 to the state of pin P1.1 */
}

The pin drivers also provide the ability to read and write entire ports of pins.

#include "mcu_pin.h"


void APP_Function(void)
{
    UINT32 values;


    values = PORT_Read(PORT_1);     /* Read all of the unmasked pins on port 1 */
    PORT_Write(PORT_2, values);     /* Write all of the unmasked pins on port 1 */
}

Pin Configuration

The pin driver for each supported MCU platform provides functions for configuring the pins. The specific configuration depends upon the MCU, since each MCU has different methods for configuring the pins. The code snippet below shows an example of configuring pins for general purpose outputs and and a UART.

#include "mcu_pin.h"


void APP_Function(void)
{
    PIN_SetDirection(P0_25, DIRECTION_OUTPUT);          /* Configure P0.25 as an output */
    PIN_SetDirection(P0_26, DIRECTION_OUTPUT);          /* Configure P0.26 as an output */

    PIN_SetFunction(P0_02, 1);                          /* Assign P0.2 to the U0_TXD function */
    PIN_SetFunction(P0_03, 1);                          /* Assign P0.3 to the U0_RXD function */
}