GPIO Module¶

The GPIO module provides an API to configure, read from, and write to the GPIO pins. Functions fall into the two categories, control and data. Control functions configure properties like direction, pin muxing, and qualification. Data functions allow you to read the value on a pin or write a value to it.

Most functions will configure a single pin at a time. The pin to be configured will be specified using its GPIO number. Refer to the device’s datasheet to learn what numbers are valid for that part number. Also note that even if a GPIO number is valid for a part number, it may not be valid for all possible features. For instance, GPIO_setAnalogMode() is only usable for a fraction of the GPIO numbers.

For information and functions to configure a pin for low-power mode wake-up, see the SysCtl module.

group gpio_api

Defines

GPIO_CTRL_REGS_STEP ((GPIO_O_GPBCTRL - GPIO_O_GPACTRL) / 2U)¶

GPIO_DATA_REGS_STEP ((GPIO_O_GPBDAT - GPIO_O_GPADAT) / 2U)¶

GPIO_DATA_READ_REGS_STEP ((GPIO_O_GPBDAT_R - GPIO_O_GPADAT_R) / 2U)¶

GPIO_GPxCTRL_INDEX (GPIO_O_GPACTRL / 2U)¶

GPIO_GPxQSEL_INDEX (GPIO_O_GPAQSEL1 / 2U)¶

GPIO_GPxMUX_INDEX (GPIO_O_GPAMUX1 / 2U)¶

GPIO_GPxDIR_INDEX (GPIO_O_GPADIR / 2U)¶

GPIO_GPxAMSEL_INDEX (0x00000014U / 2U)¶

GPIO_GPxPUD_INDEX (GPIO_O_GPAPUD / 2U)¶

GPIO_GPxINV_INDEX (GPIO_O_GPAINV / 2U)¶

GPIO_GPxODR_INDEX (GPIO_O_GPAODR / 2U)¶

GPIO_GPxGMUX_INDEX (GPIO_O_GPAGMUX1 / 2U)¶

GPIO_GPxCSEL_INDEX (GPIO_O_GPACSEL1 / 2U)¶

GPIO_GPxLOCK_INDEX (GPIO_O_GPALOCK / 2U)¶

GPIO_GPxCR_INDEX (GPIO_O_GPACR / 2U)¶

GPIO_GPxDAT_INDEX (GPIO_O_GPADAT / 2U)¶

GPIO_GPxSET_INDEX (GPIO_O_GPASET / 2U)¶

GPIO_GPxCLEAR_INDEX (GPIO_O_GPACLEAR / 2U)¶

GPIO_GPxTOGGLE_INDEX (GPIO_O_GPATOGGLE / 2U)¶

GPIO_GPxDAT_R_INDEX (GPIO_O_GPADAT_R / 2U)¶

GPIO_MUX_TO_GMUX (GPIO_O_GPAGMUX1 - GPIO_O_GPAMUX1)¶

GPIO_PIN_TYPE_STD 0x0000U¶: Push-pull output or floating input.

GPIO_PIN_TYPE_PULLUP 0x0001U¶: Pull-up enable for input.

GPIO_PIN_TYPE_INVERT 0x0002U¶: Invert polarity on input.

GPIO_PIN_TYPE_OD 0x0004U¶: Open-drain on output.

Enums

enum GPIO_Direction¶

Values that can be passed to GPIO_setDirectionMode() as the pinIO parameter and returned from GPIO_getDirectionMode().

Values:

enumerator GPIO_DIR_MODE_IN¶: Pin is a GPIO input.

enumerator GPIO_DIR_MODE_OUT¶: Pin is a GPIO output.

enum GPIO_IntType¶

Values that can be passed to GPIO_setInterruptType() as the intType parameter and returned from GPIO_getInterruptType().

Values:

enumerator GPIO_INT_TYPE_FALLING_EDGE = 0x00¶: Interrupt on falling edge.

enumerator GPIO_INT_TYPE_RISING_EDGE = 0x04¶: Interrupt on rising edge.

enumerator GPIO_INT_TYPE_BOTH_EDGES = 0x0C¶: Interrupt on both edges.

enum GPIO_QualificationMode¶

Values that can be passed to GPIO_setQualificationMode() as the qualification parameter and returned by GPIO_getQualificationMode().

Values:

enumerator GPIO_QUAL_SYNC¶: Synchronization to SYSCLKOUT.

enumerator GPIO_QUAL_3SAMPLE¶: Qualified with 3 samples.

enumerator GPIO_QUAL_6SAMPLE¶: Qualified with 6 samples.

enumerator GPIO_QUAL_ASYNC¶: No synchronization.

enum GPIO_AnalogMode¶

Values that can be passed to GPIO_setAnalogMode() as the mode parameter.

Values:

enumerator GPIO_ANALOG_DISABLED¶: Pin is in digital mode.

enumerator GPIO_ANALOG_ENABLED¶: Pin is in analog mode.

enum GPIO_Port¶

Values that can be passed to GPIO_readPortData(), GPIO_setPortPins(), GPIO_clearPortPins(), and GPIO_togglePortPins() as the port parameter.

Values:

enumerator GPIO_PORT_A = 0¶: GPIO port A.

enumerator GPIO_PORT_B = 1¶: GPIO port B.

enumerator GPIO_PORT_H = 7¶: GPIO port H.

enum GPIO_ExternalIntNum¶

Values that can be passed to GPIO_setInterruptPin(), GPIO_setInterruptType(), GPIO_getInterruptType(), GPIO_enableInterrupt(), GPIO_disableInterrupt(), as the extIntNum parameter.

Values:

enumerator GPIO_INT_XINT1¶: External Interrupt 1.

enumerator GPIO_INT_XINT2¶: External Interrupt 2.

enumerator GPIO_INT_XINT3¶: External Interrupt 3.

enumerator GPIO_INT_XINT4¶: External Interrupt 4.

enumerator GPIO_INT_XINT5¶: External Interrupt 5.

Functions

void GPIO_setInterruptType(GPIO_ExternalIntNum extIntNum, GPIO_IntType intType)¶

Sets the interrupt type for the specified pin.

This function sets up the various interrupt trigger mechanisms for the specified pin on the selected GPIO port.

Parameters

extIntNum: specifies the external interrupt.
intType: specifies the type of interrupt trigger mechanism.

The following defines can be used to specify the external interrupt for the extIntNum parameter:

GPIO_INT_XINT1
GPIO_INT_XINT2
GPIO_INT_XINT3
GPIO_INT_XINT4
GPIO_INT_XINT5

One of the following flags can be used to define the intType parameter:

GPIO_INT_TYPE_FALLING_EDGE sets detection to edge and trigger to falling
GPIO_INT_TYPE_RISING_EDGE sets detection to edge and trigger to rising
GPIO_INT_TYPE_BOTH_EDGES sets detection to both edges

Return: None.

GPIO_IntType GPIO_getInterruptType(GPIO_ExternalIntNum extIntNum)¶

Gets the interrupt type for a pin.

This function gets the interrupt type for a interrupt. The interrupt can be configured as a falling-edge, rising-edge, or both-edges detected interrupt.

Parameters

extIntNum: specifies the external interrupt.

The following defines can be used to specify the external interrupt for the extIntNum parameter:

GPIO_INT_XINT1
GPIO_INT_XINT2
GPIO_INT_XINT3
GPIO_INT_XINT4
GPIO_INT_XINT5

Return: Returns one of the flags described for GPIO_setInterruptType().

void GPIO_enableInterrupt(GPIO_ExternalIntNum extIntNum)¶

Enables the specified external interrupt.

This function enables the indicated external interrupt sources. Only the sources that are enabled can be reflected to the processor interrupt. Disabled sources have no effect on the processor.

Parameters

extIntNum: specifies the external interrupt.

The following defines can be used to specify the external interrupt for the extIntNum parameter:

GPIO_INT_XINT1
GPIO_INT_XINT2
GPIO_INT_XINT3
GPIO_INT_XINT4
GPIO_INT_XINT5

Return: None.

void GPIO_disableInterrupt(GPIO_ExternalIntNum extIntNum)¶

Disables the specified external interrupt.

This function disables the indicated external interrupt sources. Only the sources that are enabled can be reflected to the processor interrupt. Disabled sources have no effect on the processor.

Parameters

extIntNum: specifies the external interrupt.

The following defines can be used to specify the external interrupt for the extIntNum parameter:

GPIO_INT_XINT1
GPIO_INT_XINT2
GPIO_INT_XINT3
GPIO_INT_XINT4
GPIO_INT_XINT5

Return: None.

uint16_t GPIO_getInterruptCounter(GPIO_ExternalIntNum extIntNum)¶

Gets the value of the external interrupt counter.

The following defines can be used to specify the external interrupt for the

extIntNum parameter:

Parameters

extIntNum: specifies the external interrupt.

GPIO_INT_XINT1
GPIO_INT_XINT2
GPIO_INT_XINT3

Note: The counter is clocked at the SYSCLKOUT rate.

Return: Returns external interrupt counter value.

uint32_t GPIO_readPin(uint32_t pin)¶

Reads the value present on the specified pin.

The value at the specified pin are read, as specified by

pin. The value is returned for both input and output pins.

Parameters

pin: is the identifying GPIO number of the pin.

The pin is specified by its numerical value. For example, GPIO34 is specified by passing 34 as pin.

Return: Returns the value in the data register for the specified pin.

uint32_t GPIO_readPinDataRegister(uint32_t pin)¶

Reads the data register value for specified pin.

The value available at the data register for the specified pin is read, as specified by

pin. The value is returned for both input and output pins.

Parameters

pin: is the identifying GPIO number of the pin.

The pin is specified by its numerical value. For example, GPIO34 is specified by passing 34 as pin.

See: GPIO_readPin()
Return: Returns the value in the data register for the specified pin.

void GPIO_writePin(uint32_t pin, uint32_t outVal)¶

Writes a value to the specified pin.

Writes the corresponding bit values to the output pin specified by

pin. Writing to a pin configured as an input pin has no effect.

Parameters

pin: is the identifying GPIO number of the pin.
outVal: is the value to write to the pin.

The pin is specified by its numerical value. For example, GPIO34 is specified by passing 34 as pin.

Return: None.

void GPIO_togglePin(uint32_t pin)¶

Toggles the specified pin.

Writes the corresponding bit values to the output pin specified by

pin. Writing to a pin configured as an input pin has no effect.

Parameters

pin: is the identifying GPIO number of the pin.

The pin is specified by its numerical value. For example, GPIO34 is specified by passing 34 as pin.

Return: None.

uint32_t GPIO_readPortData(GPIO_Port port)¶

Reads the data on the specified port.

Return

Returns the value available on pin for the specified port. Each bit of the the return value represents a pin on the port, where bit 0 represents GPIO port pin 0, bit 1 represents GPIO port pin 1, and so on.

Parameters

port: is the GPIO port being accessed in the form of GPIO_PORT_X where X is the port letter.

uint32_t GPIO_readPortDataRegister(GPIO_Port port)¶

Reads the data written in GPIO Data Register.

Reads the data written in GPIO Data Register for the specified port. In previous devices, read of GPIO data registers resulted in read of corespoinding pins. The function

GPIO_readPortData() returns the value on pin.

Parameters

port: is the GPIO port being accessed in the form of GPIO_PORT_X where X is the port letter.

See: GPIO_readPortData()
Return: Returns the value in the data register for the specified port. Each bit of the the return value represents a pin on the port, where bit 0 represents GPIO port pin 0, bit 1 represents GPIO port pin 1, and so on.

void GPIO_writePortData(GPIO_Port port, uint32_t outVal)¶

Writes a value to the specified port.

This function writes the value

outVal to the port specified by the port parameter which takes a value in the form of GPIO_PORT_X where X is the port letter. For example, use GPIO_PORT_A to affect port A (GPIOs 0-31).

Parameters

port: is the GPIO port being accessed.
outVal: is the value to write to the port.

The outVal is a bit-packed value, where each bit represents a bit on a GPIO port. Bit 0 represents GPIO port pin 0, bit 1 represents GPIO port pin 1, and so on.

Return: None.

void GPIO_setPortPins(GPIO_Port port, uint32_t pinMask)¶

Sets all of the specified pins on the specified port.

This function sets all of the pins specified by the

pinMask parameter on the port specified by the port parameter which takes a value in the form of GPIO_PORT_X where X is the port letter. For example, use GPIO_PORT_A to affect port A (GPIOs 0-31).

Parameters

port: is the GPIO port being accessed.
pinMask: is a mask of which of the 32 pins on the port are affected.

The pinMask is a bit-packed value, where each bit that is set identifies the pin to be set. Bit 0 represents GPIO port pin 0, bit 1 represents GPIO port pin 1, and so on.

Return: None.

void GPIO_clearPortPins(GPIO_Port port, uint32_t pinMask)¶

Clears all of the specified pins on the specified port.

This function clears all of the pins specified by the

pinMask parameter on the port specified by the port parameter which takes a value in the form of GPIO_PORT_X where X is the port letter. For example, use GPIO_PORT_A to affect port A (GPIOs 0-31).

Parameters

port: is the GPIO port being accessed.
pinMask: is a mask of which of the 32 pins on the port are affected.

The pinMask is a bit-packed value, where each bit that is set identifies the pin to be cleared. Bit 0 represents GPIO port pin 0, bit 1 represents GPIO port pin 1, and so on.

Return: None.

void GPIO_togglePortPins(GPIO_Port port, uint32_t pinMask)¶

Toggles all of the specified pins on the specified port.

This function toggles all of the pins specified by the

pinMask parameter on the port specified by the port parameter which takes a value in the form of GPIO_PORT_X where X is the port letter. For example, use GPIO_PORT_A to affect port A (GPIOs 0-31).

Parameters

port: is the GPIO port being accessed.
pinMask: is a mask of which of the 32 pins on the port are affected.

The pinMask is a bit-packed value, where each bit that is set identifies the pin to be toggled. Bit 0 represents GPIO port pin 0, bit 1 represents GPIO port pin 1, and so on.

Return: None.

void GPIO_lockPortConfig(GPIO_Port port, uint32_t pinMask)¶

Locks the configuration of the specified pins on the specified port.

This function locks the configuration registers of the pins specified by the

pinMask parameter on the port specified by the port parameter which takes a value in the form of GPIO_PORT_X where X is the port letter. For example, use GPIO_PORT_A to affect port A (GPIOs 0-31).

Parameters

port: is the GPIO port being accessed.
pinMask: is a mask of which of the 32 pins on the port are affected.

The pinMask is a bit-packed value, where each bit that is set identifies the pin to be locked. Bit 0 represents GPIO port pin 0, bit 1 represents GPIO port pin 1, 0xFFFFFFFF represents all pins on that port, and so on.

Note that this function is for locking the configuration of a pin such as the pin muxing, direction, open drain mode, and other settings. It does not affect the ability to change the value of the pin.

Return: None.

void GPIO_unlockPortConfig(GPIO_Port port, uint32_t pinMask)¶

Unlocks the configuration of the specified pins on the specified port.

This function unlocks the configuration registers of the pins specified by the

pinMask parameter on the port specified by the port parameter which takes a value in the form of GPIO_PORT_X where X is the port letter. For example, use GPIO_PORT_A to affect port A (GPIOs 0-31).

Parameters

port: is the GPIO port being accessed.
pinMask: is a mask of which of the 32 pins on the port are affected.

The pinMask is a bit-packed value, where each bit that is set identifies the pin to be unlocked. Bit 0 represents GPIO port pin 0, bit 1 represents GPIO port pin 1, 0xFFFFFFFF represents all pins on that port, and so on.

Return: None.

void GPIO_commitPortConfig(GPIO_Port port, uint32_t pinMask)¶

Commits the lock configuration of the specified pins on the specified port.

This function commits the lock configuration registers of the pins specified by the

pinMask parameter on the port specified by the port parameter which takes a value in the form of GPIO_PORT_X where X is the port letter. For example, use GPIO_PORT_A to affect port A (GPIOs 0-31).

Parameters

port: is the GPIO port being accessed.
pinMask: is a mask of which of the 32 pins on the port are affected.

The pinMask is a bit-packed value, where each bit that is set identifies the pin to be locked. Bit 0 represents GPIO port pin 0, bit 1 represents GPIO port pin 1, 0xFFFFFFFF represents all pins on that port, and so on.

Note that once this function is called, GPIO_lockPortConfig() and GPIO_unlockPortConfig() will no longer have any effect on the specified pins.

Return: None.

void GPIO_setDirectionMode(uint32_t pin, GPIO_Direction pinIO)¶

Sets the direction and mode of the specified pin.

This function configures the specified pin on the selected GPIO port as either input or output.

Parameters

pin: is the identifying GPIO number of the pin.
pinIO: is the pin direction mode.

The parameter pinIO is an enumerated data type that can be one of the following values:

GPIO_DIR_MODE_IN
GPIO_DIR_MODE_OUT

where GPIO_DIR_MODE_IN specifies that the pin is programmed as an input and GPIO_DIR_MODE_OUT specifies that the pin is programmed as an output.

The pin is specified by its numerical value. For example, GPIO34 is specified by passing 34 as pin.

Return: None.

GPIO_Direction GPIO_getDirectionMode(uint32_t pin)¶

Gets the direction mode of a pin.

This function gets the direction mode for a specified pin. The pin can be configured as either an input or output The type of direction is returned as an enumerated data type.

Parameters

pin: is the identifying GPIO number of the pin.

Return: Returns one of the enumerated data types described for GPIO_setDirectionMode().

void GPIO_setInterruptPin(uint32_t pin, GPIO_ExternalIntNum extIntNum)¶

Sets the pin for the specified external interrupt.

This function sets which pin triggers the selected external interrupt.

Parameters

pin: is the identifying GPIO number of the pin.
extIntNum: specifies the external interrupt.

The following defines can be used to specify the external interrupt for the extIntNum parameter:

GPIO_INT_XINT1
GPIO_INT_XINT2
GPIO_INT_XINT3
GPIO_INT_XINT4
GPIO_INT_XINT5

The pin is specified by its numerical value. For example, GPIO34 is specified by passing 34 as pin.

See: XBAR_setInputPin()
Return: None.

void GPIO_setPadConfig(uint32_t pin, uint32_t pinType)¶

Sets the pad configuration for the specified pin.

This function sets the pin type for the specified pin. The parameter

pinType can be the following values:

Parameters

pin: is the identifying GPIO number of the pin.
pinType: specifies the pin type.

GPIO_PIN_TYPE_STD specifies a push-pull output or a floating input
GPIO_PIN_TYPE_PULLUP specifies the pull-up is enabled for an input
GPIO_PIN_TYPE_OD specifies an open-drain output pin
GPIO_PIN_TYPE_INVERT specifies inverted polarity on an input

GPIO_PIN_TYPE_INVERT may be OR-ed with GPIO_PIN_TYPE_STD or GPIO_PIN_TYPE_PULLUP.

The pin is specified by its numerical value. For example, GPIO34 is specified by passing 34 as pin.

Return: None.

uint32_t GPIO_getPadConfig(uint32_t pin)¶

Gets the pad configuration for a pin.

This function returns the pin type for the specified pin. The value returned corresponds to the values used in

GPIO_setPadConfig().

Parameters

pin: is the identifying GPIO number of the pin.

Return: Returns a bit field of the values GPIO_PIN_TYPE_STD, GPIO_PIN_TYPE_PULLUP, GPIO_PIN_TYPE_OD, and GPIO_PIN_TYPE_INVERT.

void GPIO_setQualificationMode(uint32_t pin, GPIO_QualificationMode qualification)¶

Sets the qualification mode for the specified pin.

This function sets the qualification mode for the specified pin. The parameter

qualification can be one of the following values:

GPIO_QUAL_SYNC
GPIO_QUAL_3SAMPLE
GPIO_QUAL_6SAMPLE
GPIO_QUAL_ASYNC

Parameters

pin: is the identifying GPIO number of the pin.
qualification: specifies the qualification mode of the pin.

To set the qualification sampling period, use GPIO_setQualificationPeriod().

Return: None.

GPIO_QualificationMode GPIO_getQualificationMode(uint32_t pin)¶

Gets the qualification type for the specified pin.

Return

Returns the qualification mode in the form of one of the values GPIO_QUAL_SYNC, GPIO_QUAL_3SAMPLE, GPIO_QUAL_6SAMPLE, or GPIO_QUAL_ASYNC.

Parameters

pin: is the identifying GPIO number of the pin.

void GPIO_setQualificationPeriod(uint32_t pin, uint32_t divider)¶

Sets the qualification period for a set of pins

This function sets the qualification period for a set of

8 pins, specified by the pin parameter. For instance, passing in 3 as the value of pin will set the qualification period for GPIO0 through GPIO7, and a value of 98 will set the qualification period for GPIO96 through GPIO103. This is because the register field that configures the divider is shared.

Parameters

pin: is the identifying GPIO number of the pin.
divider: specifies the output drive strength.

To think of this in terms of an equation, configuring pin as n will configure GPIO (n & ~(7)) through GPIO ((n & ~(7)) + 7).

divider is the value by which the frequency of SYSCLKOUT is divided. It can be 1 or an even value between 2 and 510 inclusive.

Return: None.

void GPIO_setAnalogMode(uint32_t pin, GPIO_AnalogMode mode)¶

Sets the analog mode of the specified pin.

This function configures the specified pin for either analog or digital mode. Not all GPIO pins have the ability to be switched to analog mode, so refer to the technical reference manual for details. This setting should be thought of as another level of muxing.

Parameters

pin: is the identifying GPIO number of the pin.
mode: is the selected analog mode.

The parameter mode is an enumerated data type that can be one of the following values:

GPIO_ANALOG_DISABLED - Pin is in digital mode
GPIO_ANALOG_ENABLED - Pin is in analog mode

The pin is specified by its numerical value. For example, GPIO34 is specified by passing 34 as pin.

Return: None.

void GPIO_setPinConfig(uint32_t pinConfig)¶

Configures the alternate function of a GPIO pin.

This function configures the pin mux that selects the peripheral function associated with a particular GPIO pin. Only one peripheral function at a time can be associated with a GPIO pin, and each peripheral function should only be associated with a single GPIO pin at a time (despite the fact that many of them can be associated with more than one GPIO pin).

Parameters

pinConfig: is the pin configuration value, specified as only one of the GPIO_::_???? values.

The available mappings are supplied in pin_map.h.

Return: None.

The first step to configuring GPIO is to figure out the peripheral muxing. The function to configure the mux registers is GPIO_setPinConfig(). The values to be passed to this function to specify the functionality the pin should have are found in pin_map.h.

Next, use GPIO_setPadConfig() to configure any properties like internal pullups, open-drain, or an inverted input signal. GPIO_setQualificationMode() and GPIO_setQualificationPeriod() can be used to configure any needed input qualification.

Then, for pins configured as GPIOs, use GPIO_setDirectionMode() to select a direction. Take care to write the desired initial value for that pin using GPIO_writePin() before configuring a pin as an output to avoid any glitches.

Several functions are provided for the configuration of external interrupts. These functions use the device’s XINT module. The Input X-BAR is also leveraged to configure the pin on which an event will cause an interrupt. These functions are GPIO_setInterruptType(), GPIO_getInterruptType(), GPIO_enableInterrupt(), GPIO_disableInterrupt(), and GPIO_setInterruptPin().

Most functions operate on one pin at a time. However, there are a few functions that can operate on an entire port at once for the sake of efficiency. These are the data functions GPIO_readPortData(), GPIO_writePortData(), GPIO_setPortPins(), GPIO_clearPortPins(), and GPIO_togglePortPins(). Other data functions that affect a single pin at a time are GPIO_readPin(), GPIO_writePin(), and GPIO_togglePin().

The code for this module is contained in driverlib/gpio.c, with driverlib/gpio.h containing the API declarations for use by applications.