Integration Guide

1.2 Low Power mode
By default, the microcontroller is in Run mode after a system or a power-on reset. In Run
mode the CPU is clocked by HCLK and the program code is executed. Several low-power
modes are available to save power when the CPU does not need to be kept running, for
example when waiting for an external event. It is up to the user to select the mode that gives
the best compromise between low-power consumption, short startup time and availab
le
wakeup sources.
The devices feature three low-power modes:
• Sleep mode (Cortex™-M3 core stopped, peripherals kept running)
•
•
Stop mode (all clocks are stopped)
Standby mode (1.2 V domain powered off)
1.3 MOS for WIFI_3V3 Power ON/OFF
External MOS for VDD_WIFI_3V3 power switch , can use one GPIO pin to control power ON/OFF