Why "STM32CubeIDE 1.5.0" limit stm32L5 "the USART source clock to provide the Smartcard clock" maximum frequency to 5MHz?

[zqizh.1]

Hi,

I can't find the information of  "the USART source clock to provide

the Smartcard clock" maximum frequency in document"RM0438

Reference manual-STM32L552xx and STM32L562xx advanced Arm®-based

32-bit MCUs".

Please advise why "STM32CubeIDE 1.5.0"  limit stm32L5 "the USART source clock to provide

the Smartcard clock" maximum frequency to 5MHz.

Thanks,

QiZhang

[TDK]

This is a smartcard limitation/requirement which is being enforced by STM32CubeMX.

https://electronics.stackexchange.com/questions/273216/smart-card-sim-clocking-requirements