Datasheet

DS12323 Rev 2 13/91
STM32L010F4/K4 Functional overview
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3 Functional overview
3.1 Low-power modes
The STM32L010F4/K4 support dynamic voltage scaling to optimize its power consumption
in Run mode. The voltage from the internal low-drop regulator that supplies the logic, can be
adjusted according to the maximum operating frequency of the system.
There are three power consumption ranges:
• Range 1 with the CPU running at up to 32 MHz
• Range 2 with a maximum CPU frequency of 16 MHz
• Range 3 with a maximum CPU frequency limited to 4.2 MHz
Seven low-power modes are provided to achieve the best compromise between low-power
consumption, short startup time and available wakeup sources:
• Sleep mode
In Sleep mode, only the CPU is stopped. All peripherals continue to operate and can
wake up the CPU when an interrupt/event occurs. The power consumption in this
mode, at 16 MHz, is about 1 mA with all peripherals off.
• Low-power run mode
This mode is achieved with the multispeed internal (MSI) RC oscillator set to the low-
speed clock (max 131 kHz), execution from SRAM or Flash memory, and internal
regulator in low-power mode to minimize its operating current. In Low-power run mode,
the clock frequency and the number of enabled peripherals are both limited.
• Low-power sleep mode
This mode is achieved by entering Sleep mode with the internal voltage regulator in
low-power mode to minimize its operating current. In Low-power sleep mode, both the
clock frequency and the number of enabled peripherals are limited; a typical example is
to have a timer running at 32 kHz.
When wakeup is triggered by an event or an interrupt, the system reverts to the Run
mode with the regulator on.
• Stop mode with RTC
The Stop mode achieves the lowest power consumption while retaining the RAM and
register contents and real time clock. All clocks in the V
CORE
domain are stopped, the
PLL, HSE input, MSI and HSI RC oscillators are disabled. The LSE or LSI is still
running. The voltage regulator is in Low-power mode.
Some peripherals featuring wakeup capability can enable the HSI RC during Stop
mode to detect their wakeup condition.
The device can be woken up from Stop mode by any of the EXTI line. In 3.5 µs, the
processor serves the interrupt or resume the code. The EXTI line source can be any
GPIO, the RTC alarm/tamper/timestamp/wakeup events, or the
USART/I2C/LPUART/LPTIM wakeup events.
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