On Suspend state, the
WL18xx chip will stay connected to Wi-Fi network and will wait for
specific "magic" frame on the Wi-Fi media. Only upon receiving that
frame, it will wake up the host. Two mode of operation are
supported:
- Suspend
state: The chip will be held in shutdown mode,
were the host disable the WLAN portion by keeping the
WLAN_Enable signal OFF, in that mode the WL18xx consumes
minimal current consumption.
- WOWLAN
state: The host is shutting down but the WLAN
chip is being kept active (WLAN enable pin remains active).
This allows the WL18xx firmware to remain active during
suspend and if the system is configured to allow the WLAN
interrupt to wake-up the host, it can trigger a system
resume when a specific packet is received by the WL18xx
firmware.
Before you enter suspend
mode, you need to declare which event triggers the wake up. In this
example, the trigger is set to “any”, which means any event (console
activity, magic frame, and so forth) will wake up the board:
There are two options to
resume from Suspend:
- Serial console
activity or other configured wakeup sources (keypad,
touchscreen) will trigger resume.
- Send Magic frame
from other Station to the Station that is in suspend
mode.