topic Re: LCP1114 overclocking GPIO in LPCXpresso IDE

LCP1114 overclocking GPIO

lpcware — Wed, 15 Jun 2016 21:29:08 GMT

Content originally posted in LPCWare by kisiel on Thu Jul 18 07:45:49 MST 2013
Hello,
I found random behavior of my LCP1114/301. I overclocked CPU to 60Mhz and I think problems with random values of GPIO comes from overclocking. I need to keep up frequency at 60Mhz to fit timmings but I got random values on PIO. I have tried, histeressis, pull up, pull down, etc.
It is possible to downclock only GPIO?
Thanks in advance.

Re: LCP1114 overclocking GPIO

lpcware — Wed, 15 Jun 2016 21:29:08 GMT

Content originally posted in LPCWare by rmteo on Thu Jul 18 18:18:38 MST 2013
Why are you surprised that you are having issues when operating beyond published specs for a device?

Re: LCP1114 overclocking GPIO

lpcware — Wed, 15 Jun 2016 21:29:09 GMT

Content originally posted in LPCWare by rmteo on Thu Jul 18 18:33:48 MST 2013
Try 120MHz instead.

Re: LCP1114 overclocking GPIO

lpcware — Wed, 15 Jun 2016 21:29:09 GMT

Content originally posted in LPCWare by kisiel on Sat Aug 17 15:20:09 MST 2013
I expected good result at 48Mhz also, but GPIO gives me random values on 5V signal,
in assy is:
ldr r1,=GPIO
ldr r0,[r1]
ldr r2,[r1]
cmp r0,r2
...
I have tried so far:
pull up pull down hysteresis on/off, I checked signals with logic analyser (e.g. USBee-AX-Pro) and source signals are "flat" in time then GPIO is read.
I will change cortex M0 to M3 maybe this will help.