What error is in the UART receive FIFO?

Discussion created by lpcware Employee on Jun 15, 2016
Content originally posted in LPCWare by sravet on Thu Oct 03 00:02:24 MST 2013
I am working with UART2 on an LPC1768 part.  It is connected to an RF remote receiver that outputs data at 9600 baud.  I have configured UART2 for 9600 baud and verified that it works correctly by connecting it to my laptop via a USB/TTL serial converter.  Characters I type on the laptop are correctly received by the 1768.

However when I connect to the RF receiver I see constant line errors.  The LSR value I read is 0xe1.  This indicates RXFE (error in RX FIFO), Transmitter empty, and receiver data ready.  This doesn't make sense to me -- There is an error in the RX fifo, but none of the LSR error bits (break, parity, frame, overrun) are set.  What error is bit 7 indicating?