3.4 Interrupt Handling and I/O Line Control
PIO on the SAM E70/S70/V70/V71 MCUs and EIC on the PIC32CZ CA80/CA9x MCUs.
Key Similarities:
- Signal Handling: Both PIO and EIC manage external signals (pins) and can generate interrupts or trigger events based on input states.
- Interrupt Capability: Both PIO and EIC can be configured to trigger interrupts based on changes in the state of external pins, such as rising or falling edges.
Key Differences:
- Functionality:
- PIO: Primarily designed
to manage general-purpose I/O pins, offering flexibility to configure
pins as either inputs or outputs. It can trigger interrupts based on pin
state changes, but it is more focused on general I/O control and
interfacing. The PIO peripheral is a more flexible and broader I/O
handling system that can be used for a variety of purposes, such as
GPIO, communication interfaces, and so on.
Each I/O line of the PIO Controller features the following:
Debouncing filter, multi-drive capability, additional interrupt modes enabling rising edge, falling edge, low-level or high-level detection on any I/O line, and so on.
- EIC: Specifically designed for handling external interrupts. It allows more sophisticated configurations for edge detection (for example, rising, falling, or both), as well as filtering, debouncing, and edge counting. It is a more specialized peripheral for precise interrupt management triggered by external events.
- PIO: Primarily designed
to manage general-purpose I/O pins, offering flexibility to configure
pins as either inputs or outputs. It can trigger interrupts based on pin
state changes, but it is more focused on general I/O control and
interfacing. The PIO peripheral is a more flexible and broader I/O
handling system that can be used for a variety of purposes, such as
GPIO, communication interfaces, and so on.
- Pin Configurations:
- PIO typically has a broader set of pin control options and can be configured to handle multiple functions beyond just interrupts, such as regular digital I/O (input or output), analog functions, or specialized interfaces, such as UART or SPI.
- EIC is focused solely on interrupt-related functionality and typically supports fewer pins with a strong focus on interrupt triggering.
- Interrupt Priority and Features:
- PIO can trigger interrupts but may not have the same fine-grained control over interrupt priority, filtering, or response time that the EIC offers. The EIC peripheral is often preferred for handling critical interrupts due to its dedicated interrupt management features.