lpcware

LPC812 UART Baud Rate Issue (faster than expected)

Discussion created by lpcware Employee on Jun 15, 2016
Latest reply on Jun 15, 2016 by lpcware
Content originally posted in LPCWare by mvinger on Sat Jun 22 20:14:34 MST 2013
I found a weirdness and searched all the docs to discover what my error might be. I used a board to board UART channel setup at 115200 and all seemed to work fine. I then went to hook-up a separate UART receiver-only for some simple IR remote stuff (someone else's remote). It only sends two bytes in N81 at 300 bps. The RX-only channel would not work. Then I noticed an elongated data pattern from what I got to what was sent.
I hooked up the logic analyzer and verified the 300bps on the RX-only channel and the data was as expected. I then halved the baudrate setting sent to initialize the channel and wala (however you spell it), I could read the data appropriately.
I then checked my 115200bps full-duplex UART channel and it was running at 250kbps.
Anyone have a clue as to if there is an error in the docs or am I missing something else.
The LPC812 is configured to run at the max 30MHz from the internal osc as the base. The UART div is set to 1 so the PLL clock should match the 30MHz system clock.

Perplexed!

MTV2

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