STMicroelectronics STM32F405 Reference Manual page 540

Advanced-control timers (TIM1&TIM8)
Note: The break inputs is acting on level. Thus, the MOE cannot be set while the break input is
active (neither automatically nor by software). In the meantime, the status flag BIF cannot
be cleared.
The break can be generated by the BRK input which has a programmable polarity and an
enable bit BKE in the TIMx_BDTR Register.
There are two solutions to generate a break:
•
By using the BRK input which has a programmable polarity and an enable bit BKE in
the TIMx_BDTR register
• By software through the BG bit of the TIMx_EGR register.
In addition to the break input and the output management, a write protection has been
implemented inside the break circuit to safeguard the application. It allows you to freeze the
configuration of several parameters (dead-time duration, OCx/OCxN polarities and state
when disabled, OCxM configurations, break enable and polarity). You can choose from 3
levels of protection selected by the LOCK bits in the TIMx_BDTR register. Refer to
Section 17.4.18: TIM1&TIM8 break and dead-time register (TIMx_BDTR) on page
LOCK bits can be written only once after an MCU reset.
Figure 123
540/1731
shows an example of behavior of the outputs in response to a break.
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RM0090
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