The examples in this section are based on polling the status of UART by continuously checking the flags of UART_SR. The write operation contains a busy loop that can spin for several milliseconds, depending on the length of the string. Even worse, the read function presented earlier spins within a busy loop until there is data to read from the peripheral, which means that the whole system is hanging until new data is received. In a single-thread embedded system, returning to the main loop with the shortest latency possible is important to keep the system responsive.
The correct way to perform UART communication without blocking is by using the interrupt line associated with UART to trigger actions based on the ...
