GPIO stands for General Purpose Input/Output. It’s a basic pin on a microcontroller that can be configured as either an input or an output.
GPIO pins can be used for various purposes. They are not specialized for any particular function, which gives designers flexibility. GPIOs can be used to implement basic digital communication protocols like bit-banging, where software directly manages the high and low states of pins to emulate communication protocols
GPIOs provide a simple and low-overhead mechanism to interact with the outside world. For many simple tasks, using dedicated hardware interfaces can be overkill and costly. GPIOs offer a cost-effective way to achieve many functionalities.
GPIO pins often can be configured to generate interrupts on specific conditions, like a rising edge, falling edge, or both. This is useful for event-driven tasks. While named “General Purpose,” GPIO pins on many MCUs can also serve alternate functions, such as communication interfaces (SPI, I2C, UART) or analog inputs.
In Aurix, TC375LK, Each Port module “Port slice” controls a set of assigned General Purpose Input/Output (GPIO) port lines which are connected to pads connected to device pins/balls.
Depending on its configuration a Port module can have the following features:
– Controls up to 16 port lines.
– Enables SW to control the output of each port line.
– Output modification registers ease clearing, setting and toggling of single port lines and nibbles of port lines
without affecting the state of other port lines.
– Enables SW to read the input value of each port line.
– Multiplexes up to 7 alternate functions to each output.
– Supports direct I/O control by a peripheral on a per-line granularity.
– The emergency stop feature allows to switch off the output driver of configurable port lines by SMU or special port pins.
– In packages with reduced pin count the Port module can disable selected pins.
Most of the digital GPIO lines have an emergency stop logic. This logic makes it possible to individually disconnect outputs and put them onto a well-defined logic state in an emergency case. In an emergency case, the pin is switched to an input function with internal pull-up device connected or tri-state (depending on global configuration). The Emergency Stop Register Pn_ESR determines whether an output is enabled or disabled in an emergency case.
Each 32-bit wide port input/output control register controls four GPIO port lines:
Register Pn_IOCR0 controls the Pn.[3:0] port lines
Register Pn_IOCR4 controls the Pn.[7:4] port lines
Register Pn_IOCR8 controls the Pn.[11:8] port lines
Register Pn_IOCR12 controls the Pn.[15:12] port lines

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An Article by: Yashwanth Naidu Tikkisetty
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