LPC1837 USART

[lpcware]

Content originally posted in LPCWare by taz9557 on Wed Apr 02 13:22:29 MST 2014
Hi
I’m using LPC1837 running at 180MHz in my project, I need to use USART2,3 as high speed half duplex RS485 (baud rate = 6Mbits). I’ve configured my hardware and got it running up to 3Mbits without any problem but any speed above this receives incorrect characters in without any framing errors. i.e. if I transmit 0x55 I receive 0x5B. Has anyone come across this problem or has anyone got a suggestion.
Your help be most appreciated. Thanks

[lpcware]

Content originally posted in LPCWare by xianghuiwang on Thu Apr 17 17:08:08 MST 2014
Hi, taz9557,

Can you check is you run into the following limitation?

If the fractional divider is active (DIVADDVAL > 0) and DLM = 0, the value of the DLL register must be 3 or greater.

This is a direction quote from the user manual.

In general, over 3Mbits is no problem, but no all the desired rates are available.

regards,