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STM32F42xx and STM32F43xx silicon limitations
STM32F42xx and STM32F43xx
DocID023833 Rev 5
2.5
USART peripheral limitations
2.5.1
Idle frame is not detected if receiver clock speed is deviated
Description
If the USART receives an idle frame followed by a character, and the clock of the transmitter
device is faster than the USART receiver clock, the USART receive signal falls too early
when receiving the character start bit, with the result that the idle frame is not detected
(IDLE flag is not set).
Workaround
None.
2.5.2
In full duplex mode, the Parity Error (PE) flag can be cleared by
writing to the data register
Description
In full duplex mode, when the Parity Error flag is set by the receiver at the end of a
reception, it may be cleared while transmitting by reading the USART_SR register to check
the TXE or TC flags and writing data to the data register.
Consequently, the software receiver can read the PE flag as '0' even if a parity error
occurred.
Workaround
The Parity Error flag should be checked after the end of reception and before transmission.
2.5.3
Parity Error (PE) flag is not set when receiving in Mute mode
using address mark detection
Description
The USART receiver is in Mute mode and is configured to exit the Mute mode using the
address mark detection. When the USART receiver recognizes a valid address with a parity
error, it exits the Mute mode without setting the Parity Error flag.
Workaround
None.