The STM8L15xxx embeds an internal voltage regulator for generating the 1.8 V power
supply for the core and peripherals. This regulator has two different modes:
● Main voltage regulator mode (MVR) for Run, Wait for interrupt (WFI) and Wait for event
(WFE) modes.
● Low power voltage regulator mode (LPVR) for Halt, Active-halt, Low power run and Low power
wait modes.