General-Purpose Input/Output (GPIO) Availability and Low-Power Modes#

The SiWG917 device operates in multiple power states, each designed to optimize power consumption based on system activity.

General-Purpose Input/Output (GPIO) availability depends on the power domain (System-on-Chip/High-Performance (SoC/HP), Ultra-Low-Power (ULP), or Ultra-Ultra-Low-Power (UULP)) associated with the selected power mode.

This section describes GPIO accessibility and wake-up capabilities across the different operating and low-power states.

Active Mode#

In Active mode, the SiWG917 SoC is fully operational, and GPIO availability depends on the power domain active in the selected power state.

The following table summarizes GPIO accessibility across active power states (PS4/PS3/PS2):

Description#

• PS4 / PS3: All GPIO domains (HP, ULP, UULP) are active and can be used for standard operation.

• PS2: High-performance (HP) GPIOs are powered down to save energy, while ULP and UULP GPIOs remain active.

Sleep Mode#

In Sleep mode, the SiWG917 reduces power consumption by disabling the SoC/HP and ULP domains, while retaining critical functions within the UULP domain.

Only UULP GPIOs remain operational and can serve as wake-up sources.

GPIO Availability in Sleep Mode#

Description#

• Wake-Up Source:
  UULP GPIOs can trigger wake-up events to transition the device from Sleep state back to the corresponding Active state.

• Use Case:
  Ideal for applications requiring extremely low power with selective GPIO-based wake-up (e.g., button press or external interrupt).

Standby Mode#

Standby mode offers a faster wake-up time compared to Sleep mode, though it consumes slightly more power.

In this mode, the CPU clock is gated, and any valid interrupt event can transition the system back to the Active state.

GPIO Availability in STANDBY Mode#

Description#

• Wake-Up Capability:
  Any interrupt is capable of bringing the device out of Standby mode.

• Advantages:

  • Faster resume time compared to Sleep mode.

  • Useful when the system requires periodic wake-ups or faster response to external events.

Note:
Power consumption in Standby mode is higher than in Sleep mode, but wake-up latency is significantly lower.

Shutdown Mode#

In Shutdown mode, the SiWG917 consumes the lowest possible power.

All domains are powered down except the UULP domain, which retains minimal functionality to detect wake-up events.

GPIO Availability in Shutdown Mode#

Description#

• Wake-Up Source:
  Only UULP GPIOs can bring the system out of Shutdown mode.
  Typical triggers include external events such as a button press or Real-Time Clock (RTC) alarm.

• Use Case:
  Suitable for battery-powered applications that require long-term standby operation with minimal energy drain.
  Upon wake-up, the device reboots and reinitializes the SoC and peripheral subsystems.

Summary of GPIO Behavior Across Power Modes#

The following table summarizes GPIO functionality and wake-up capabilities across all power modes of the SiWG917 device.