What are the NOPs for?

[EmbeddedAleks]

Why does the PCH compiler put NOPs at the begining of each function? Not only is it the waste of MPU time but the FLASH too.
Does anybody know a way to get rid of that?

Thanks,
Alex
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This message was ported from CCS's old forum
Original Post ID: 144514895

[PCM programmer]

<font face="Courier New" size=-1>:=Why does the PCH compiler put NOPs at the begining of each function? Not only is it the waste of MPU time but the FLASH too.
:=Does anybody know a way to get rid of that?
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These two posts will answer your questions:
<a href="http://www.pic-c.com/forum/general/posts/10339.html" TARGET="_blank"> <a href="http://www.pic-c.com/forum/general/posts/10339.html" TARGET="_blank">http://www.pic-c.com/forum/general/posts/10339.html</a></a>
<a href="http://www.pic-c.com/forum/general/posts/10347.html" TARGET="_blank"> <a href="http://www.pic-c.com/forum/general/posts/10347.html" TARGET="_blank">http://www.pic-c.com/forum/general/posts/10347.html</a></a>

Also see the link to the Piclist discussion below:</font>
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This message was ported from CCS's old forum
Original Post ID: 144514896

[R.J.Hamlett]

:=Why does the PCH compiler put NOPs at the begining of each function? Not only is it the waste of MPU time but the FLASH too.
:=Does anybody know a way to get rid of that?
:=
:=Thanks,
:=Alex
Read the 'errata' sheet for the processor.
This is required on the 18F family, when there are jumps going beyond 4000H. _Provided_ your code is small enough to not need such jumps, you can turn this off, using the device editor. If your processor does haave code beyond this address, you have to leave these present, to get round a hardware problem with the chip (not CCS's fault).

Best Wishes
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This message was ported from CCS's old forum
Original Post ID: 144514903

[Douglas Kennedy]

These NOP's are needed to work around a huge error made by Microchip. How this error ever got through testing and into production boggles the mind? Maybe they had Arthur Anderson or the Enron management do their testing. Sadly Microchip chose not to recall the chips. NOP is Microchip's mneumonic for Not our Problem.
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This message was ported from CCS's old forum
Original Post ID: 144514905

[EmbeddedAleks]

Thanks for the quick replies guys. That's right it is a silicon bug.
I am not clear on how to get rid of it if my code is LT 4000h bytes though. I am not really sure what the "device editor" is you mentioned.

Alex
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This message was ported from CCS's old forum
Original Post ID: 144515007

[PCM programmer]

:=Thanks for the quick replies guys. That's right it is a silicon bug.
:=I am not clear on how to get rid of it if my code is LT 4000h bytes though. I am not really sure what the "device editor" is you mentioned.
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This is a screen-shot of it:
<a href="http://www.ccsinfo.com/pix/pcw3-big.gif" TARGET="_blank">http://www.ccsinfo.com/pix/pcw3-big.gif</a>
You have to buy the whole PCW package to get this.

I wouldn't mind if they made it a stand-alone program
and sold it for $25 extra with the PCM compiler.
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This message was ported from CCS's old forum
Original Post ID: 144515009