it seems to be running happily at 64hmz
i dont understand why since i tried 2 different 10mhz crystals
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it seems to be running happily at 64hmz
i dont understand why since i tried 2 different 10mhz crystals
"I think fish is nice, but then I think that rain is wet, so who am I to judge?" - Douglas Adams
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To be really quiet with that ...Originally Posted by Kamikaze47
I only buy my Xtals from Farnell, now ... per 100, price is nice.
Never more from a local dealer ...
Alain
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Why insist on using 32 Bits when you're not even able to deal with the first 8 ones ??? ehhhhhh ...
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IF there is the word "Problem" in your question ...
certainly the answer is " RTFM " or " RTFDataSheet " !!!
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The only thing to watch when overclocking is that things like serial comms ad the like often wont work. I had an 18F4580 running on a 20Mhz xtal with the HS_PLL setting - whilst it wasn't probably running at 80Mhz, it was dammed fast- but non of my serial comms would work until I replaced the 20Mhz xtal with a 12Mhz one. (as spotted by Alain)
I was going to suggest that you tried using the xtal from the breadboard that you know was a proven crystal... but now you seem to of resolved the problem. - I have to agree with Alain, I would only purchase from a large component retailer (RS in my case).
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I'm still noticing something strange.
When I turn it on for the first time in half an hour, it takes about 3 seconds to start running.
If I then turn it off, and back on it starts right away.
Still something strange going on.
"I think fish is nice, but then I think that rain is wet, so who am I to judge?" - Douglas Adams
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Hi, MalcThe only thing to watch when overclocking is that things like serial comms ad the like often wont work. I had an 18F4580 running on a 20Mhz xtal with the HS_PLL setting - whilst it wasn't probably running at 80Mhz, it was dammed fast
I was going to suggest that you tried using the xtal from the breadboard that you know was a proven crystal... but now you seem to of resolved the problem. - I have to agree with Alain, I would only purchase from a large component retailer (RS in my case).
your problem was setting correctly the OSC related registers ... not a Xtal problem ...
as you were running @ ... 4x 12 Mhz !!!
for PBP ... it is not overclocking, as those frequencies are in the compiler's list ...
@ Kamikaze
looks there's a supply stability or glitches problem that doesn't allow the PLL to stabilize quickly ... add a 10/22 µF Tantalum bead as close as possible to the PIC !!!
You also can poll for the PLL stability flag before allowing your program to run ... ( for execution sake )
Alain
Last edited by Acetronics2; - 4th September 2010 at 15:55.
************************************************** ***********************
Why insist on using 32 Bits when you're not even able to deal with the first 8 ones ??? ehhhhhh ...
************************************************** ***********************
IF there is the word "Problem" in your question ...
certainly the answer is " RTFM " or " RTFDataSheet " !!!
*****************************************
|
The only SMD tantalum cap I had handy was 1uF so I soldered it as close to the pic's supply pins as possible and it seems to have fixed the issue.
I'll know for sure once I've left it off night and turn it back on.
Thanks heaps for your help.
"I think fish is nice, but then I think that rain is wet, so who am I to judge?" - Douglas Adams
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Glad you finally see the end ...
Et ... YES, PLL's are very sensitive to supply !!!
************************************************** ***********************
Why insist on using 32 Bits when you're not even able to deal with the first 8 ones ??? ehhhhhh ...
************************************************** ***********************
IF there is the word "Problem" in your question ...
certainly the answer is " RTFM " or " RTFDataSheet " !!!
*****************************************
|
still no luck unfortunately
when i turned it on after it being off over night, it took 3 mins to start running.
once it was running it seems to work fine, and turning it off and back on results in a quick start up.
the time it takes to start seems to be proportional to the time that it's been off.
"I think fish is nice, but then I think that rain is wet, so who am I to judge?" - Douglas Adams
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