How is UART data reception handled in ISR?
The CPU initializes the UART receive hardware so that it fires an interrupt signal whenever a new byte of data is received. And in the ISR code, we save the received data in a buffer for further processing. This way of handling the UART data reception is a non-blocking way.
How does UART Receive buffering work in a FIFO?
Lesson 10: UART Receive Buffering. A FIFO is a type of buffer (or queue) in which the data enters and exits in the same the order. If the FIFO is full and there is another piece of data to enter, it is either dropped (the newest data is lost) or the oldest data in the FIFO is pushed out and discarded.
What happens if UART peripheral does not receive data?
Otherwise, and if the UART peripheral for some reason didn’t receive the expected amount of data, the function will keep blocking the CPU for a certain amount of time “time-out” after which it gets terminated and gives back the control to the CPU to resume the main code.
Is there a way to receive UART serial data?
And obviously, it’s not an efficient way to receive serial data despite the fact that it does actually work. Using interrupt signals is a convenient way to achieve serial UART data reception. The CPU initializes the UART receive hardware so that it fires an interrupt signal whenever a new byte of data is received.
How to receive UART serial data with STM32?
This way of handling the UART data reception is a non-blocking way. As the CPU initiates the receiving process and it resumes executing the main code. Until an interrupt is received, then it freezes the main context and switches to the ISR handler to save the received byte to a buffer and switches back to the main context and resume the main code.
How does the callback function work in STM32 Hal?
Further, if you find that the callback is not being triggered even if you are sending enough data to the peripheral, make sure the interrupt is actually enabled – the HAL_UART_Receive_IT function doesn’t actually enable the interrupt, that has to be done during initialization of the peripheral. Thanks for contributing an answer to Stack Overflow!