LPC4350 issues

[lpcware]

Content originally posted in LPCWare by tom.varghese on Fri Apr 06 08:26:21 MST 2012
Hello All,

We built an LP4350 board as prototype and have run into some very fundamental issues.  This could be because this is our first NXP device or we didn't read the documentation/FAQs adequately.  So I apologize if this is obvious to you.

So here is what we have run into:

1) 12MHz crystal won't oscillate, we tried different caps, etc. We tried the resonator that was used on an eval board, etc.  We then put a 12MHz oscillator, now the chip seems to be up and running, at least LPCExpresso is able to download code into RAM and run.
2) 32.768KHz crystal won't oscillate, tried a variety of caps, etc.
3) We tried to boot off of SPI flash, but no luck on that either.

We really need to get this design working, if there are any professionals that are willing to work with us for a short period to get this going, that would be great.

Thanks in advance for any help.

--Tom V.

[lpcware]

Content originally posted in LPCWare by PhilYoung on Fri Apr 06 09:47:44 MST 2012
duplicate deleted

[lpcware]

Content originally posted in LPCWare by PhilYoung on Fri Apr 06 09:46:59 MST 2012

The device boots from the internal oscillator initially, so there is no need for an Xtal.

The Xtal Oscillator has to be enabled by SW in the XTAL_OSC_CTRL register which is in the battery bbacked power domain, presumably you remembered to set these bits and allows the oscillator time to start before switching the main clock over to it?.

initially all importantclocks should be derived from BASE_SAFE_CLK which is the internal IRC clock.

regards

Phil.