UART receive

Discussion created by lpcware Employee on Jun 15, 2016
Latest reply on Jun 15, 2016 by lpcware
Content originally posted in LPCWare by IanB on Sat Aug 09 13:49:42 MST 2014
I've missed something here, and I can't find what it is:

My UART will transmit but does not receive.

I have a nice clear signal on RXD (on the pin, not just the track leading to the pin, it IS soldered down!), at the right baud rate (checked on the 'scope), but the UART shows nothing happening.
The RDR bit of the line status register stays permanently low.

1. The same routine works on an LPC1224
2. I have configured the RXD pin as RXD (0xC1 in the IOCONFIG)
3. If I configure it as a GPIO pin, I can check the signal and it is present.
4. It's a version 302 of the LPC1113, so there is not an alternative pin for RXD
5. The UART is in line-break on the TXD side (but I have tried turning off line-break and it makes no difference)

Could somebody tell me - I'm sure it's obvious!