STM32F407IE datasheet(27/154 Pages) STMICROELECTRONICS

27 / 154 page

STM32F405xx, STM32F407xx

Description

Doc ID 022152 Rev 1

27/154

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.

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.

STM32F407IE Datasheet(PDF) 27 Page - STMicroelectronics