The UART driver demo tries to use the FIFOLVL register in prvFillFifoFromBuffer. AFAICT, the register isn’t present on LPC17xx parts and has been removed from the user manual. It seems that the you can only check whether the FIFO is completely empty. There is some discussion on this topic here: http://knowledgebase.nxp.com/showthread.php?t=2231

Oh, thanks for pointing that out.  I made the mistake of using the user manual and CMSIS drivers as a reference, obviously ;o)  Unfortunately I just released V1.0.1 a couple of days ago.  I’m planning (hopefully) to do a major upgrade to improve the user model a bit in the near future though. Regards.

Thanks! Yeah, it’s a bummer that NXP never updated their CMSIS drivers or added an errata for this.