Digital Output Pins¶
Description¶
General-purpose digital output pins
This resource implements a single or an array of digital output pins, supporting manual control from task code. The pins are mapped in the I/O Mapping Panel .
When the SCIF driver is initialized, the pins are by configured to operate in digital output mode, with initial output value as specified per resource I/O usage.
When the SCIF driver is uninitialized, the pins are returned to the MCU domain GPIO module, with desired pull level (no pull, pull-down or pull-up). Note that the uninitialization does not modify the GPIO module’s output enable settings, and it is assumed that the pins have not been configured as outputs.
Name and Label¶
A short name and a descriptive label must be specifed for each I/O usage:
- The name is used for references in task code, for example as parameter to
gpioSetOutput(). For a name XYZ:- If selecting accessed by constant , a single constant
AUXIO_O_XYZis created automatically - If selecting accessed by look-up table , a data structure member
cfg.pAuxioOXyz[]is created automatically
- If selecting accessed by constant , a single constant
- The label is displayed in the I/O Mapping Panel , and is also used in automatically generated code documentation
Output Drive Strength¶
Output drive strength is configurable per resource I/O usage, with the same options as in the SDK-provided PIN or GPIO driver.
See the device datasheet to find which I/O pins have high-drive capability.
Examples¶
Changing Pin Output¶
// Set a single pin. Using a constant as parameter is fast (1 instruction cycle) because all calculations
// can be done at compile-time and the iobset instruction can be used.
gpioSetOutput(AUXIO_O_LED);
// Clear an array of pins. Using a variable as parameter is slower (10 instruction cycles) because
// all calculations must be done at run-time and the iobclr instruction cannot be used.
for (U16 n = 0; n < LED_COUNT; n++) {
gpioClearOutput(cfg.pAuxioOLeds[n]);
}
Procedures Overview¶
| Name | Brief description |
gpioCfgMode() |
Changes the mode of a single digital GPIO pin. More … |
gpioClearOutput() |
Clears a single GPIO output pin (to low). More … |
gpioDisableInputBuf() |
Disables the input buffer for a digital GPIO pin. More … |
gpioEnableInputBuf() |
Enables the input buffer for a digital GPIO pin. More … |
gpioGenPulseTrain() |
Generates a pulse train with specified polarity and active/inactive duration on the specified AUX I/O pin. More … |
gpioGetInputValue() |
Gets the value of a single GPIO input pin. More … |
gpioSetOutput() |
Sets a single GPIO output pin (to high). More … |
gpioToggleOutput() |
Toggles a single GPIO output pin (to low if previously high, or to high if previously low). More … |
Constants¶
| Name | Description |
GPIO_MODE_INPUT |
GPIO mode: Input |
GPIO_MODE_OPEN_DRAIN |
GPIO mode: Open-drain (can be driven low) |
GPIO_MODE_OPEN_SOURCE |
GPIO mode: Open-source (can be driven high) |
GPIO_MODE_OUTPUT |
GPIO mode: Output |
Global Variables¶
None.
Procedures¶
gpioCfgMode¶
Prototype: gpioCfgMode(auxio, mode)
Changes the mode of a single digital GPIO pin. The pin can be configured as output, input/analog, open-drain or open-source.
Use gpioEnableInputBuf() and gpioDisableInputBuf() to control the pin input buffer. The buffer should be disabled when a pin is allowed to float.
Note: For pins with internal pull-up or pull-down, the pull resistor is enabled also in output mode. Driving against a pull resistor increases current consumption.
Note: This procedure is more efficient if the auxio and mode parameters are specifed as constants (rather than variables).
Parameter value(s)¶
- auxio : The GPIO pin to be configured (index of AUX I/O pin)
- mode : New GPIO pin mode (GPIO_MODE_XYZ)
gpioClearOutput¶
Prototype: gpioClearOutput(auxio)
Clears a single GPIO output pin (to low).
Note: This procedure is more efficient if the auxio parameter is specifed as a constant (rather than a variable).
Parameter value(s)¶
- auxio : The GPIO pin to be cleared (index of AUX I/O pin)
gpioDisableInputBuf¶
Prototype: gpioDisableInputBuf(auxio)
Disables the input buffer for a digital GPIO pin.
The GPIO pin can only be read when the input buffer is enabled.
The input buffer should be disabled when the GPIO pin is floating.
Note: This procedure is more efficient if the auxio parameter is specifed as a constant (rather than a variable).
Parameter value(s)¶
- auxio : The GPIO pin to disable input buffer for (index of AUX I/O pin)
gpioEnableInputBuf¶
Prototype: gpioEnableInputBuf(auxio)
Enables the input buffer for a digital GPIO pin.
The GPIO pin can only be read when the input buffer is enabled.
The input buffer should be disabled when the GPIO pin is floating.
Note: This procedure is more efficient if the auxio parameter is specifed as a constant (rather than a variable).
Parameter value(s)¶
- auxio : The GPIO pin to enable input buffer for (index of AUX I/O pin)
gpioGenPulseTrain¶
Prototype: gpioGenPulseTrain(#auxio, #polarity, #activeDuration, #inactiveDuration, count)
Generates a pulse train with specified polarity and active/inactive duration on the specified AUX I/O pin.
Parameter value(s)¶
- #auxio : The GPIO pin to be pulsed (index of AUX I/O pin)
- #polarity : The value of the pulse (1 = high, 0 = low) during the active phase
- #activeDuration : Duration of the active phase, in number of 12 MHz periods (1 to 256)
- #inactiveDuration : Duration of the inactive phase, in number of 12 MHz periods (3 to 256)
- count : Length of the pulse train in number of pulses (1 to 65535)
gpioGetInputValue¶
Prototype: gpioGetInputValue(auxio; value)
Gets the value of a single GPIO input pin.
Parameter value(s)¶
- auxio : The GPIO pin to be checked (index of AUX I/O pin)
Return value(s)¶
- value : The GPIO pin value (1=high, 0=low)
gpioSetOutput¶
Prototype: gpioSetOutput(auxio)
Sets a single GPIO output pin (to high).
Note: This procedure is more efficient if the auxio parameter is specifed as a constant (rather than a variable).
Parameter value(s)¶
- auxio : The GPIO pin to be set (index of AUX I/O pin)
gpioToggleOutput¶
Prototype: gpioToggleOutput(auxio)
Toggles a single GPIO output pin (to low if previously high, or to high if previously low).
Note: This procedure is more efficient if the auxio parameter is specifed as a constant (rather than a variable).
Parameter value(s)¶
- auxio : The GPIO pin to be toggled (index of AUX I/O pin)