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:
  1. 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.
  2. 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.
  3. 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.