USART2 RXNE Interrupt Handling in C: Reading Data from Receive Buffer

This code snippet checks if the USART2 RXNE (Receive Data Register Not Empty) interrupt flag is set. If the flag is set, it means that there is data available to be read from the USART2 receive buffer.

If the flag is set, the code reads the data from the USART2 data register (USART2->DR) and stores it in the variable 'd'. Then, it adds the data to the 'rxbuf' array at the current 'rxlen' index and increments 'rxlen' by 1.

Note that this code assumes that 'rxbuf' and 'rxlen' are defined somewhere in the code and that appropriate error handling and buffer overflow prevention mechanisms are in place.