The internal oscillator can operate up to 16 MHz, but the maximum clock frequency depends on the voltage and temperature range. Refer to the datasheet for specific details.
The watchdog timer can be configured using the WWDG_CR register. Set the WWDG_CR[WDGA] bit to enable the watchdog timer, and set the WWDG_CR[WDGTB] bits to set the timeout period.
The NPOR and NPER bits control the flash memory protection. NPOR (Number of Pages to be Written) sets the number of pages to be written, and NPER (Number of Pages to be Erased) sets the number of pages to be erased.
To use the UART in asynchronous mode, set the UART_CR2[TXE] bit to enable the transmitter, and set the UART_CR2[RXE] bit to enable the receiver. Configure the baud rate using the UART_BRR registers.
The IWDG (Independent Watchdog) timer is used to reset the microcontroller if the software becomes stuck or hangs. The WWDG (Window Watchdog) timer is used to monitor the software execution and reset the microcontroller if it does not receive a refresh signal within a specified time window.