STM32F407IG datasheet(28/180 Pages) STMICROELECTRONICS

28 / 180 page

Description

STM32F405xx, STM32F407xx

28/180

Doc ID 022152 Rev 3

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 the 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 / wakeup /

tamper / time stamp events, the USB OTG FS/HS wakeup or the Ethernet 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 1.2 V domain is powered off. The

PLL, the HSI RC and the HSE crystal oscillators are also switched off. After entering

Standby mode, the SRAM and register contents are lost except for registers in the

backup domain and the backup SRAM when selected.

The device exits the Standby mode when an external reset (NRST pin), an IWDG reset,

a rising edge on the WKUP pin, or an RTC alarm / wakeup / tamper /time stamp event

occurs.

The standby mode is not supported when the embedded voltage regulator is bypassed

and the 1.2 V domain is controlled by an external power.

Note:

When in Standby mode, only an RTC alarm/event or an external reset can wake up the

device provided VDD is supplied by an external battery.

2.2.19

VBAT operation

The VBAT pin allows to power the device VBAT domain from an external battery, an external

supercapacitor, or from VDD when no external battery and an external supercapacitor are

present.

VBAT operation is activated when VDD is not present.

The VBAT pin supplies the RTC, the backup registers and the backup SRAM.

Note:

When the microcontroller is supplied from VBAT, external interrupts and RTC alarm/events

do not exit it from VBAT operation.

2.2.20

Timers and watchdogs

The STM32F405xx and STM32F407xx devices include two advanced-control timers, eight

general-purpose timers, two basic timers and two watchdog timers.

All timer counters can be frozen in debug mode.

Table 3 compares the features of the advanced-control, general-purpose and basic timers.

STM32F407IG Datasheet(PDF) 28 Page - STMicroelectronics