AN1516: SiWG917 General Purpose Input/Output (GPIO) Debugging Application Note#

The SiWG917 is a highly integrated wireless System-on-Chip (SoC) that combines advanced processing, power management, and connectivity capabilities for modern IoT applications.
A key component of its flexibility lies in its General Purpose Input/Output (GPIO) subsystem, which provides extensive configurability across multiple power domains and enables efficient control, signaling, and interfacing with peripheral components in both active and low-power states.

This application note provides detailed guidance on the SiWG917 GPIO architecture, configuration, and operation.
It explains how GPIOs are distributed across different power domains (System-on-Chip/High-Performance (SoC/HP), Ultra-Low-Power (ULP), and Ultra-Ultra-Low-Power (UULP)) and describes their functional characteristics, electrical parameters, and configuration procedures.
In addition, it covers interrupt management, special use cases such as Radio Frequency (RF) switch control and debug interfaces, and low-power GPIO behavior, including GPIO state retention and wake-up mechanisms.

The content is intended for firmware and hardware engineers working on Wi-Fi, Bluetooth Low Energy (BLE), and multi-protocol IoT platforms based on the SiWG917.

Key Objectives#

  • GPIO Classification and Power Domains: Gain a clear understanding of how GPIOs are categorized into SoC/HP, ULP, and UULP domains.

  • GPIO Configuration and Functional Modes: Learn how to configure GPIOs for input, output, or alternate functions using the WiSeConnect Software Development Kit (SDK) application programming interfaces (APIs). Understand port and pin mapping, direction control, and initialization flow to ensure reliable signal operation.

  • Advanced GPIO Features: Explore advanced configuration options, including pull-up/down states, drive strength selection, and slew rate control.

  • GPIO Interrupts and Wake-Up Mechanisms: Implement GPIO-based interrupts for responsive event handling and configure wake-up triggers to restore system activity from low-power modes.

  • Best Practices and Troubleshooting: Review design best practices and common troubleshooting techniques to ensure stable and predictable GPIO operation.