Cortex-M3 discontinued (at least for TI models)

[alexisnik]

Hello everyone,

It seems that Cortex M3 is being replaced by Cortex M4F, at least for Stellaris TI series. I believe that other manufacturers are also moving to Cortex M4F, as it is supposed to have many advantages over the Cortex M3, the most significant of which is floating point support and better manufacturing method. I might as well be wrong for manufacturers other than Texas, but I think that others will follow too.

I think that for those who consider creating new designs, you should go directly to Cortex M4F based mcu, that is, if it also suits you.

Cheers,

Alex

[spasbyspas]

Hello!
By your logic then you should for all applications to use the most out of new microcontrollers in the market.
I understand that you're excited about that core microcontrollers, but each application has its own appropriate architecture.

[metal]

in case all companies moved to M4F, what alex said is applicable regardless of your worries about the application..

[bobcat1]

Hi

Ti Cortex M3 was an old chip dune on 250 nm process who have many bugs and large power consumption.
I believe this is the reason for his extermination, the M4F is steel expensive in compeer to M3F and not totally P2P compatible

All the best
Bobi  

[alexisnik]

Hello!
By your logic then you should for all applications to use the most out of new microcontrollers in the market.
I understand that you're excited about that core microcontrollers, but each application has its own appropriate architecture.

spasbyspas, it seems that you have not even read what I am writing (and yet you jumped in to conclusions and charectirization)!

I am not at all "excited" by new chips etc. In fact, the purpose of writing this was that I have based several new designs in the Cortex M3, only to find that it has been discontinued! For this reason, I am warning others that they might face the same problem, so to save them from trouble, this is a warning based on a problem that I currently face.

Hi

Ti Cortex M3 was an old chip dune on 250 nm process who have many bugs and large power consumption.
I believe this is the reason for his extermination, the M4F is steel expensive in compeer to M3F and not totally P2P compatible

All the best
Bobi 

The M4F is supposed to be cheaper (at least that is what Texas sais for the future, based on manufacturing costs). As you say, it is still expensive, but I hope it will drop. It is definately NOT pin compatible, and therefore this is why I try to warn other people, because they will need to change their design, like me. The problem is that the Stellaris M4F are still new, and they don't have the features of the Stellaris Cortex M3 (yet!), like Ethernet, EPI, etc.

So currently I am in the position which for at least six months I will have to "hunt down" the Stellaris ICs, while waiting for new M4F models with Ethernet at least...

[spasbyspas]

Hello!
Do not worry Stelaris with Cortex-M3 core microcontrollers will continue to produce for a long time.
Despite the large number of bugs will still be used in many applications because of its unique integrated peripherals.
In your last sentence, not specifically for any company refers your recommendation to switch to M4F architecture,
so that supposedly treats for all manufacturers.
It's good before you post a message to read it.

[alexisnik]

As I said, I don't know about other manufacturers, but I am worried that others will follow Texas for the same reasons.

As for continuing the production of Cortex M3, I am quoting the following from TI forum (post of a TI employee):

You guys make fair points. "No changes" to availability was perhaps not the best choice of words, since we have taken explicit action to remove LM3S from distributor inventories and lead times are long. Texas Instruments is taking action against LM3S promotion, not only for the LM4F parts.

I recognize the timing isn't optimal, not without the ENET devices in production, which is one of the key reasons why the NRND will not turn to obsoletion. Customers that have platform designs on the LM3S can continue their production or platform developments knowing that we will not EOL the devices. The webpages and documentation are still online if you search for the individual part number, just they are not linked from our homepage.

I also understand you and other LM3S community members have invested time, expertise, and reputation on these parts and the transition to NRND has been painful, especially if you are using ENET devices. I apologize on behalf of our group for that pain. As for an explanation, I can tell you that even though we are extremely proud of the technological achievements that the LM3S products brought to the market, we know we have done so much better on the LM4F that we feel compelled to incentivize a transition. Better means less errata, shorter lead times, more performance, lower power, and yes, lower cost of manufacturing. This will translate to concrete benefits for the new community of TI Cortex-M users.

So as you can see, even if they are still produced, it will be hard to find them with long lead times. Therefore, for small projects this is not acceptable, and the option of continuing to work with the Stellaris M3 is not really an option. if you have a finished product with standard unit sales / month, sure, you can order MCUs every six months....

I did read it, and I explicitly said that I don't know if it applies for other manufacturers, just in the previous line. As for the unique integrated peripherals, it seems that M4 and M4F also have the same features + DSP (+FPU for M4F). Just not for TI... (unlucky me!).

[spasbyspas]

Strange, really strange because with colleagues over a month ago we did a short query and the answer was that the production of CM3 Stelaris will continue.

[alexisnik]

It WILL continue. However, I guess it will not be available (in stock) from major destributors, like Farnell,Mouser, Digikey... I don't know about you, but for us it is a major problem, we will either have to switch to a different manufacturer or buy stock which we might end up not using...

[miserable]

Hi,
In this segment, (M0 to M4) NXP is the market leader and defines the rules.
For high end market (A8, Omap..) TI is dominant.

NXP just produces ARM microcontroller and there are no any other architecture in their portfolio.
I think M3 life cycle is not maturated yet for NXP and at least more than 1 year we they would dominate M3.

Just manufacturing a silicon core is not enough alone to force the designer to use it.
It requires a lot of reference design, development boards, SW migrations, documentations, application notes, success stories, porting of RTOS/stack/application etc.

So I think we can go 2 years with M3.

Best regards.

[alexisnik]

NXP just produces ARM microcontroller and there are no any other architecture in their portfolio.
I think M3 life cycle is not maturated yet for NXP and at least more than 1 year we they would dominate M3.

The M3 from TI did not seem at all to be at the end of its life, so that was why I was so surprised to find that within one month it became NRND...

Just manufacturing a silicon core is not enough alone to force the designer to use it.
It requires a lot of reference design, development boards, SW migrations, documentations, application notes, success stories, porting of RTOS/stack/application etc.

I am not sure what you mean here... If you mean Texas, then they have done this as much as they can, by giving the Stellaris M4 launchpad at a promotional price of 5$ (now it costs 12$). Also the migration is supposed to be really easy...

I guess time will tell!!

[bigtoy]

I don't work for TI, however I know a number of people who do. TI has had many problems manufacturing the Luminary Micro M3 parts. Some of those problems have been made public, some not. The problem has not been with the ARM core - the problem has been with Luminary Micro's (now TI's) implementation of it. There have been a lot of process and design related issues - the cost of moving these parts to a new foundry process (and fixing the design issues at the same time) was going to be far too high. The parts were aewsome when they first came out - remember that Luminary Micro had the very first M3 parts on the market. Now there's so much competition it's a very different ball game. The writing has been on the wall for these parts for quite some time.

I don't think you should infer this to be anything except a TI problem. ST, NXP, and many many others are still going gangbusters with the M3 core. Manufacturers are continuing to announce new processors containing the M3.  You might be surprised that even TI is doing so, although in a different way. For example their new AM335x processor (single-core Cortex-A8) contains an M3 co-processor. TI has simply decided not to compete any longer in the standalone M3 marketplace.

[alexisnik]

Thank you very much for this answer! It cleared things up, for me at least. Sorry if I have caused panic in other people who used non-TI M3 processors.

Could you please provide any inside info like this on the Concerto processor? I want to use it in a project, but I am really afraid to do it, in case it becomes NRND too... Thanks in advance!

[bigtoy]

I have a concerto development kit here, and the company I work for uses piccolo processors (same family as the concerto) in a variety of products. I've seen the TI roadmap for the family and it extends out for some years and many parts. These processors are coming out of a different (and very well established) group within TI than the Stellaris (Luminary Micro) parts. They are very price-competitive and appear to be winning a good number of design slots. I don't think you need to have any concerns about these parts. Certainly the company I work for isn't concerned at all, and is quite committed to using parts from that family.

[alexisnik]

That is great news, as I have already purchased 2x (Concerto + C2000 motor control kit) to develop a motor drive based on Concerto!

[sn00p]

The amount of issues we had with a Luminary processor almost drove us to despair.  Supply was constrained and we had to be careful about which revision chips we were getting because some had more critical issues than others.

Needless to say, we only used a TI/Luminary part in one product and then moved on!  Nice middleware but zero confidence in the silicion.

We've never experienced issues like we had with them with any other ARM vendor.

[Mentor]

About 10 years ago TI did the same thing, just discontinuing some chips without warning. I don't remember exactly which lines they did this, but since then a lot of development guys started to look to TI with some suspicion.

For small companies like the one I used to work for, the costs to change to a completely new line of chips are way to high, usually leaving too little profit behind.

[hef4015]

I spoke to some TI representatives last year and they said that TI tries to sell even older silicon for quite some years. As some mentioned earlier the ICs might be harder to get and it will definitely take longer.

Regarding the Stellaris series I read that there were some problems with the flash memory. Too bad I have one design where the integrated Ethernet PHY is used.

[bigtoy]

Yes, there were problems with data retention on some of the flash-based parts (the flash would start losing its contents after a relatively small number of erase - program cycles, which is a big problem for any kind of data-logging application). The integrated ethernet PHY was pretty unique. They subsequently moved away from doing that because the PHY generates a fair amount of heat, which causes its own problems. But it did make for a really small formfactor solution.

[hef4015]

The integrated PHY was the feature I liked the most.
I did a quick search for some other ARM controller with integrated PHY and couldn't find any except some hard to buy parts which require purchases in high quantities.
If anyone has an idea, I would appreciate it.

[spasbyspas]

... and finaly - TI M4 with Ethernet MAC+PHY
http://www.ti.com/lsds/ti/arm/arm_cortex_m_microcontrollers/arm_cortex_m4/stellaris_arm_cortex_m4f/overview.page
http://www.ti.com/lit/sg/spmt285b/spmt285b.pdf
... starting from TQFP-128 pins 0.4 ...

[alexisnik]

Yes, at last!

They also have a dev kit, with the Tiva+Ethernet. Glad we didn't depend on the Stellaris this year, it would have been a disaster...

[hef4015]

Thanks for the update. 
These are good news. It is a little late for a project I finished this year.  When there is an updated needed there is a new platform to do it.

[Al-Amoudi]

There are various ARM Cortex-M3 implementations by ST , TI NXP and others.
Which is the easiest to use. 

[spasbyspas]

There is no single answer, everyone would meet and the determined preferred company. I mostly work with ST.