LPC11A14 UART question

Discussion created by lpcware Employee on Jun 15, 2016
Content originally posted in LPCWare by tyassin on Tue Mar 04 06:11:52 MST 2014

I have read the datasheet for this device and have a question about IIR-register.
In this register there is a flag in IIR[3:1] that can give you status of the UART. One of these flags are when IIR[3:1] is 0x3 'Receive Line Status (RLS)'. In this register, which now is called Line status register(LSR?????) is the first bit 0 'RDR(Receive Data Ready)' if there is data ready to be read from FIFO.

My question is what is the difference between this flag and the when the status of IIR[3:1] is 0x02 'Receive Data Available(RDA)'?

Thank you