UART RX ISR firing many times in a row - LPC11A14

Discussion created by lpcware Employee on Jun 15, 2016
Latest reply on Jun 15, 2016 by lpcware
Content originally posted in LPCWare by tyassin on Wed Sep 10 07:03:46 MST 2014

I have a question about the UART RX ISR.
I am having a communication between a PC and my controller LPC11A14. I use an UART ISR for the receive part. The communication is running fine for a while. I have placed a pin that toggle when I am inside my UART ISR. Suddenly I can see, on my scope monitoring the communication, that I get a enormous number of UART ISR firing straight after another and the controller simply freezes and I have to toggle the power.

My question is what can cause the UART to fire interrupts like that?
I know that to clear the interrupt flag, I have to read the buffer: LPC_USART->RBR

Anybody having any idea how an UART RX ISR can make these hundreds of interrupts???

Thank you.