MCF5272 Replacement processor

[vishwanathgaonk]

Do we have software compatible, Longevity supported replacement processor for MCF5272 either from ColdFire Series or Kinetic Series? As MCF5272 is Not recommended for new designs. 

[TomE]

If changing to another part is too difficult, you can always resort to a "Last Time Buy". Project your production for the next 2, 5 or more years, and do a bulk-buy now. That could be the cheapest option. Make sure you're working somewhere else before the company runs out of parts and this problem just got a lot worse, but for someone else :-).

> As MCF5272 is Not recommended for new designs

According to the Product Page, the "MCF5272VM66R2" is still "Active", although it is the only one in the list.

So which one are you using if not that one, and can you change over to that one?

Maybe not.

The Parameter Page says that variant doesn't have Ethernet! There's nothing anywhere else (User Manuals etc) that says they ever made one of these without Ethernet. There's nothing I can find that lists the different variants either, or details the differences between the "VM66", "VF66" and "VM66R2". Is that correct or is that a mistake on the Parameter Page?

Is there any documentation on the "MCF5272VM66R2" part anywhere? Or anything describing the different part variants? This is usually under "Ordering Information" in the Data Sheet for this part. The MFC5272 doesn't have a Data Sheet - the electrical data is in the back of the User's Manual, and that hasn't been updated since 2007.

Tom

[miduo]

Hi,

 The MCF5272 family is really so old and it is not recommend for new design. We do not provide any direct replacement part for it any more. We highly recommend customer may migrate to Kinetis, but it need a re-design.

[vishwanathgaonk]

I completely understand that there is hardware redesign required however I would like to keep software impact minimal. 

Do you have any recommendation on any Kinetic Series  which is similar in nature?  I need one ethernet port and few serial ports 

[TomE]

> I would like to keep software impact minimal. 

> Do you have any recommendation on any Kinetic Series  which is similar in nature?

Those statements are mutually exclusive. Kinetis uses a little-endian ARM CPU. Your existing code runs on a big-endian Coldfire chip. If you want "minimal software impact" then you'll want to run on a big-endian CPU. That means another (newer) ColdFire or perhaps a Power chip. Except that has different register sets, interrupt control and everything else.

Of course if your code is written to run on a proper Operating System, then getting it running on a different chip that that OS supports should just be a matter of recompiling. I'm assuming you're not that lucky.

If you're changing the code to run on an ARM core, then the peripherals will be the least of your worries.

Almost every chip (Kinetis or Coldfire) has Ethernet and two UARTs like the MCF5272 does.

You're using such an old chip, there's nothing published that will tell you the "nearest chip". You'll have to do the selection work yourself. But that shouldn't take you more than an hour at the most.

So how long do you want the next design to last for? Jumping to ARM will be a lot harder, but should give you a longer life (and an easier jump to another ARM micro next time). Otherwise I'd suggest you pick another Coldfire chip.

So the next things are how fast does it have to be (MCF5272 is 66MHz)? How much RAM (only 4k on MCF5272)? Are you using external RAM? How much? What's the external Flash? You might be able to pick a newer chip that has enough RAM or FLASH internally, making the design simpler and cheaper.

Another possible consideration (more of a diversion) is to try to find a parts with similar or identical UARTs and Ethernet. That would be difficult as the MCF5272 uses UARTs 'Based on MC68681 DUART. That's not likely to have been used in something newer. But all UARTs are basically the same, and it shouldn't take more than a few hours to convert the friver code from one sort of UART to another one. Porting an Ethernet driver is a bit harder. Freescale have used a few different Ethernet cores in their chips. To find out if you've got a match (between the MCF5272 and whatever chip you're considering) just compare FEC register names between the Reference Manuals. The quick shortcut is to look for a register with a weird name (like "ETDSR") and type that into the Search Field on this site. That will list the Reference Manuals with the same registers. I get 528x, 521x, 5272 (surprise!), 52235 and some MCP chips.

You should start at the "Longevity" link in my last post. You'll get 15 years from 2007 for the 532c, 537x and 5251. Most of the MCF51 series gets you 10 and 15 years from 2012. At least keep that page open to annotate the ones that have the peripherals and memory you need.

To find which chips have the peripherals and memory you want, you can try to use the product pages, but I wouldn't recommend that. I'd suggest you download this:

http://cache.nxp.com/files/microcontrollers/doc/brochure/BRCOLDFIRESUM.pdf?fsrch=1&sr=1&pageNum=1 

MCF51CN128: Ethernet and 3 SCI (UART). Also 24k RAM and 128k Flash. But only 10 years from 2009.

MCF5223x, MCF5225x: Ethernet and 3 UARTs. Also 32k-64k RAM and 128k-512k Flash. But 10 years from 2007.

Not looking good. The ones with long life don't have Ethernet (MCF5251), and the ones with Ethernet don't have a long life. The only exception to that seems to be the MCF5441x which has 15 years from 2010. Except that one runs at 250MHz, has two Ethernet ports, *TEN* UARTs, is in a 256 pad BGA and runs DDR2 memory. Probably a bit more powerful , expensive and hard to "load and feed" than you need.

So your best bet is the MCF5225x, but that's only guaranteed until November 2018. That's better than what you have, and it isn't listed as "not recommended for new designs" yet. It may also have the same Ethernet as your current one, or at least close enough to make the software easy.

Tom

[TomE]

It depends on which hardware modules you require. If all you need is the CPU and memory, then anything will work. If you need everything, then I doubt it. You'll just have to port your software to a different CPU.

That CPU is so old it doesn't even show up on the Archived Longevity Page:

http://www.nxp.com/pages/product-longevity-archived-september-2014:LONGEVITY-ARCHIVED

Here's a document saying how to port from the MCF5272 to MCF5282, except that one is obsolete too. Also the App Note is dated 2003 (together with the one saying how to go from MC68302 to MCF5272):

http://cache.freescale.com/files/product/doc/AN2394.pdf

http://cache.freescale.com/files/netcomm/doc/app_note/AN2457.pdf

We would like to move away from the MCF5235, but it is really something special because of the TPU. Nothing has that and the other peripherals it has.

If you go from Coldfire to ARM you may have endian problems.

Tom

[yibbidy]

Hi Tom,

I don't want to hijack this thread but FYI with your MCF5235 upgrade path, there is the new MPC5746R with 2 x eTPU's + flash + analog etc, even QFP package if you need that.   Available for 15 years from March this year.  Probably cheaper than the MCF5235 too.

Cheers, Shaun

[TomE]

Thank you for your suggestion on this chip family. It has the advantages of being big-endian, and we're also using other MPC chips in other products. They are mainly unsuitable for MCF5235 replacement for what we need. The MPC5746R has 4M of Flash and 320k of SRAM internally. It has up to 252 pins, but doesn't put a fast parallel memory bus or DDR controller on any of them. We need at least 512M of external NOR Flash and 8M of external fast RAM (SDR or DDR) that we can run code from. I'll have a more detailed look at the family next week.

Tom

[yibbidy]

Oh I see, that is one highly kitted out Coldfire V2 you have there!  I don't know of any MPC chips with both an eTPU and an external address bus, but I've really only looked into MPC microcontrollers.  As you say, it appears that the MCF5235 is something special.

Cheers, Shaun