Datasheet

DS9716 Rev 11 27/139
STM32F401xB STM32F401xC Functional overview
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3.19.2 General-purpose timers (TIMx)
There are seven synchronizable general-purpose timers embedded in the
STM32F401xB/STM32F401xC (see Table 4 for differences).
• TIM2, TIM3, TIM4, TIM5
The STM32F401xB/STM32F401xC devices are 4 full-featured general-purpose timers:
TIM2, TIM5, TIM3, and TIM4.The TIM2 and TIM5 timers are based on a 32-bit auto-
reload up/downcounter and a 16-bit prescaler. The TIM3 and TIM4 timers are based on
a 16-bit auto-reload up/downcounter and a 16-bit prescaler. They all feature four
independent channels for input capture/output compare, PWM or one-pulse mode
output. This gives up to 16 input capture/output compare/PWMs on the largest
packages.
The TIM2, TIM3, TIM4, TIM5 general-purpose timers can work together, or with the
other general-purpose timers and the advanced-control timers TIM1 and TIM8 via the
Timer Link feature for synchronization or event chaining.
Any of these general-purpose timers can be used to generate PWM outputs.
TIM2, TIM3, TIM4, TIM5 all have independent DMA request generation. They are
capable of handling quadrature (incremental) encoder signals and the digital outputs
from 1 to 4 hall-effect sensors.
• TIM9, TIM10 and TIM11
These timers are based on a 16-bit auto-reload upcounter and a 16-bit prescaler.
TIM10 and TIM11 feature one independent channel, whereas TIM9 has two
independent channels for input capture/output compare, PWM or one-pulse mode
output. They can be synchronized with the TIM2, TIM3, TIM4, TIM5 full-featured
general-purpose timers. They can also be used as simple time bases.
3.19.3 Independent watchdog
The independent watchdog is based on a 12-bit downcounter and 8-bit prescaler. It is
clocked from an independent 32 kHz internal RC and as it operates independently from the
main clock, it can operate in Stop and Standby modes. It can be used either as a watchdog
to reset the device when a problem occurs, or as a free-running timer for application timeout
management. It is hardware- or software-configurable through the option bytes.
3.19.4 Window watchdog
The window watchdog is based on a 7-bit downcounter that can be set as free-running. It
can be used as a watchdog to reset the device when a problem occurs. It is clocked from
the main clock. It has an early warning interrupt capability and the counter can be frozen in
debug mode.
3.19.5 SysTick timer
This timer is dedicated to real-time operating systems, but could also be used as a standard
downcounter. It features:
• A 24-bit downcounter
• Autoreload capability
• Maskable system interrupt generation when the counter reaches 0
• Programmable clock source.
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