Wake-on-WLAN GPIO Signal Waveform Encoding

The patent changes the parameter of the GPIO signal from a simple binary state to a multi-state signal with different waveform characteristics (rising edge, falling edge, pulse width). By varying these signal parameters, the Wi-Fi circuit can encode different wake-up reasons (e.g., wake-up packet, magic packet, connection establishment) that the system circuit can distinguish and respond to appropriately.

The patent implements a preliminary action by having the system circuit perform a wake-up phase before entering deep sleep mode. During this phase, the system circuit remains in a low-power state but maintains the capability to detect and respond to GPIO signals. This preliminary preparation ensures that when the Wi-Fi circuit needs to wake up the system, the system is already prepared to receive and process the wake-up signal, thus maintaining reliability while saving power.

The patent applies partial action by implementing a two-stage wake-up process. In the first stage (wake-up phase), the system circuit performs only essential operations to exit sleep mode and become responsive to signals. In the second stage (recognition phase), the system circuit completes the full wake-up procedure to recognize the Wi-Fi circuit and determine the specific wake-up reason. This partial action approach significantly reduces the initial wake-up time from hundreds of milliseconds or seconds to a much faster response, while still maintaining the ability to determine wake-up reasons when needed.