Mature PICs

[Charlie U]

Has anyone else had a chance to review the latest Product Selection Guide on Microchip's website?

http://ww1.microchip.com/downloads/en/DeviceDoc/00148K1.pdf

Check out pages 20 and 21 of the pdf file, and read it and weep!! Our trusted 18F452 and its siblings (458, 252 etc.) are now listed as "Not recommended for new designs".

I realize that there are "direct" replacements, but these parts are fairly new and the errata sheet has 6 pages of problems, mostly with the MSSP and ECCP. Does anyone have experience with these new parts (18F4520, etc.) and can calm my fears. Remember how long it took to get the 18F452 working!?!

Also, I'll add another gripe, Microchip has confirmed that none of the new parts are available in the PLCC package. That package is (was?) nice because it is SMT, there are sockets available that fit the same foot print, and there are emulator adapters that transition from the DIP package to the PLCC. Their story is that they are having a difficulty sourcing the lead frame, and there are problems with socket reliability.

It looks like those of us with emulators will now need to purchase the Device Adapters and Transition Sockets, and dedicate a prototype to development.

Just blowing off steam.

Charlie

[PCM programmer]

Yes, but you can still get older parts such as the 16c54.
I checked a couple US distributors, http://www.digikey.com
and http://www.future-active.com and they both have it.
So I assume that Microchip is still making it.

The only one I know of that has been truly discontinued
is the 16C84. If you go to the web page for it, here:
http://www.microchip.com/stellent/idcplg?IdcService=SS_GET_PAGE&nodeId=1335&dDocName=en010180
they say "Obsolete/EOL".

The 18F452 is in stock at Digikey with over 9500 pieces available
in the PLCC package.

The 18F4520 is also in stock, but only 3 package types are available
and the highest stock quantity is 124 pieces.

I hope this provides some reassurance.

[Guest]

There are some good new features: PIC184520 allows three breakpoints... This should make a debug session much easier.

Bad issue is has the new EUSART which has many problems, at low xtal F there are serious issues with using high Baud rates(PIC18F6621), Auto Baud is also a problem, last time I talked with mc they told me to find a chip with the older uart. !

So along as they keep making pin compatible chips I'm not too worried.

For anyone buying small quantities of PIC chips, Digikey has a price break at 25pcs. for most PIC's. if you need less than 25 Mouser has the best prices. Mouser does the digikey 25pcs price for 1pcs.

[kender]

[sjbaxter]

Most of my projects have been developed on the 'not reccomended' 18F258. I've since replaced these in my final product with the 18F2580 and 18F2680.

No issues at all apart from a slight cost increase, the devices were selected after I had commited to PCB design. But the benifits far out-way that:

I now have 64K of Flash to play with, more RAM, Enhanced CAN with more receive/transmit buffers, UARTS that support LIN, 3 breakpoints (which has been a lifesaver in debugging my latest code changes) .... and all in a pin to pin compatible package.

Yes, the new devices do have issues and hence more errata info. But you do get a lot more functionality and options for your money.
_________________
Regards,
Simon.

[SLomas]

That's great untill you (me!) develop based on a 18F458, find that at the end of development that device is no longer recommended for new designs. Just switch to the 4580..... but now I have to buy a £300 upgrade for my compiler as my version does not support the 4580!
If I were cynical I might suggest that Microchip & CCS were in cahoots over this!

[sjbaxter]

SLomas, your development cycle must be very big !! My compiler (PCH) supported the newer microchip replacements long before they announced that the 18F2x8 series 'were not recommended for new designs'.

Anyway, the PCH upgrade is only £90 ish (for a one of buy) and I've only done an upgrade every 18 months (rather than the rolling maintenence contract) and I haven't missed anything.

It sounds like its time you invested in some upto date tools

You should try and keep up with microsoft's MSDN subscription if you think a single compiler is expensive.
_________________
Regards,
Simon.

[SLomas]

My development cycle is not big, I'm just slow!
I thought I was being clever buying the PCWH version to get support for all sizes of PIC & debugging with the ICDU40, but this means a bigger bill to upgrade. I can see the sense in buying the individual compilers & renewing as & when required as you suggest.
My version 3.207 does not support the 4580, though it does support some of the devices of a similar era like the 2620, though I notice that the fuses are not calculated correctly - this version must have been a work in progress for this range of PICs.
I guess that I must check the Microchip mature list more often and write my bugs faster in future!