Power Up reset/execution problem

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 Sun Jul 21 09:44:27 MST 2013
I have two boards powered in series (one board receives power and passes it on to second via cable).
Both boards have an LPC812. The board at the end of the power chain is the UI board and is the master over the internal UART interface and the board providing the power is the mainboard as is the UART slave.

On power up, the mainboard LPC812 always powers up and executes its code properly.
The UI board at the end of the power chain must be manually reset externally for it to execute its code.
Is there a power up sequence/rate issue? I did not see any restrictions in the data sheet. The biggest difference on the UI board is has a 5V rotary encoder connected to 2 input pins.

Thank you.