Smart power management is possible using the advanced clock control architecture which allows the STM8S to switch from a low speed to high speed clock in 2µS. The STM8S consumes 8 mA ~ 10 mA at 16 MHz when running from Flash and 2.5 mA ~ 4.5 mA when running from SRAM. In Wait mode, the CPU is off but the oscillator and peripherals continue to run consuming 1.2 mA from the internal 16 MHz RC or 500 µA from the 128 kHz RC oscillator. In Active Halt the designer can choose between a wake up time of 2 µS and 200 µA consumption or a wake up time of 100 µS and 11 µA consumption. In Active Halt the device can be woken up by either the AWU or an external interrupt. In Halt Mode the device is consuming 4.5 µA and can be woken by an external interrupt.