LPC55S28 UART RX IDLE INTERRUPT

playbear — Fri, 16 Jan 2026 10:00:40 GMT

Hello,NXP!

I'm using LPC55S28 in my project,and I find that LPC55S28 DO NOT SUPPORT uart rx idle interrupt or Character Time-out Indicator (CTI) like LPC1768???

for example , if I set 15 to rx fifo trig level , I send only 1 bytes to LPC55S28, how do I know there is 1 byte data in rx fifo?No way to notice/trig user application to know there is 1 byte in rx fifo?What I can do is polling the fifo stat all the time?

Please help me, give me some better ideas?Thank you.

Re: LPC55S28 UART RX IDLE INTERRUPT

danielholala — Fri, 16 Jan 2026 15:09:20 GMT

With LPC55xx having no support for RX TIMEOUT, you are best of with reading single bytes only. I'm successfully using USART_TransferReceiveNonBlocking() requesting only 1 byte at at time.

topic Re: LPC55S28 UART RX IDLE INTERRUPT in LPC Microcontrollers

LPC55S28 UART RX IDLE INTERRUPT

Re: LPC55S28 UART RX IDLE INTERRUPT