CD00161566 Datasheet, PDF (16/105 Pages) STMicroelectronics – nullMedium-density performance line ARM-based 32-bit MCU

Description
STM32F103x8, STM32F103xB
2.3.11
2.3.12
Note:
in reset mode when V_DD is below a specified threshold, V_POR/PDR, without the need for an
external reset circuit.
The device features an embedded programmable voltage detector (PVD) that monitors the
V_DD/V_DDA power supply and compares it to the V_PVD threshold. An interrupt can be
generated when V_DD/V_DDA drops below the V_PVD threshold and/or when V_DD/V_DDA is
higher than the V_PVD threshold. The interrupt service routine can then generate a warning
message and/or put the MCU into a safe state. The PVD is enabled by software.
Refer to Table 11: Embedded reset and power control block characteristics for the values of
V_POR/PDR and V_PVD.
Voltage regulator
The regulator has three operation modes: main (MR), low power (LPR) and power down.
 MR is used in the nominal regulation mode (Run)
 LPR is used in the Stop mode
 Power down is used in Standby mode: the regulator output is in high impedance: the
kernel circuitry is powered down, inducing zero consumption (but the contents of the
registers and SRAM are lost)
This regulator is always enabled after reset. It is disabled in Standby mode, providing high
impedance output.
Low-power modes
The STM32F103xx performance line supports three low-power modes 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.
 Stop mode
The Stop mode achieves the lowest power consumption while retaining the content of
SRAM and registers. All clocks in the 1.8 V domain are stopped, the PLL, the HSI RC
and the HSE crystal oscillators are disabled. The voltage regulator can also be put
either in normal or in low power mode.
The device can be woken up from Stop mode by any of the EXTI line. The EXTI line
source can be one of the 16 external lines, the PVD output, the RTC alarm or the USB
wakeup.
 Standby mode
The Standby mode is used to achieve the lowest power consumption. The internal
voltage regulator is switched off so that the entire 1.8 V domain is powered off. The
PLL, the HSI RC and the HSE crystal oscillators are also switched off. After entering
Standby mode, SRAM and register contents are lost except for registers in the Backup
domain and Standby circuitry.
The device exits Standby mode when an external reset (NRST pin), an IWDG reset, a
rising edge on the WKUP pin, or an RTC alarm occurs.
The RTC, the IWDG, and the corresponding clock sources are not stopped by entering Stop
or Standby mode.
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