lpc23xx, capacitor on reset pin

[lpcware]

Content originally posted in LPCWare by m2babaey on Sat Jun 29 21:24:20 MST 2013
Hi
I am having start up problems with lpc23xx devices. i.e sometimes the CPU does not start my code when power is connected
I activated brown out by changing PCON register and the situation got better
when I reduce the pull up resistor or the capacitor I have on the reset pin, the situation gets better

Finally I removed the capacitor and there was only a 39k pull up resistor on reset pin and the problem was solved. The core was starting normal operation each time I connected power

My question is that will this cause a problem if I don't use a capacitor on reset pin?
What other solution do you suggest to solve this problem?

[lpcware]

Content originally posted in LPCWare by m2babaey on Mon Jul 01 05:24:04 MST 2013
I looked at my supply voltage by oscilloscope and there was 500mV AC on my 3.3V Although I had 10 x100nF capacitors on the chip
I added an electrolytic capacitor and now my circuit starts working even when I have 100nF capacitor on reset pin

Just there is one more problem. I have a switch that connects reset pin to GND. When I apply a low to the reset pin, the chip stops and doesn't restart when I remove the low level on the reset pin
I looked at the links, maybe the chip is entering ISP mode. but I have a 10K pull up resistor on P2.10. what else should I do?
This is interesting that when jtag connector is connected to the board, the reset switch works fine and the CPU restarts normally after reset

[lpcware]

Content originally posted in LPCWare by R2D2 on Sun Jun 30 05:58:56 MST 2013

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Quote: m2babaey
My question is that will this cause a problem if I don't use a capacitor on reset pin?
What other solution do you suggest to solve this problem?

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See #4 of http://knowledgebase.nxp.com/showthread.php?t=4220