ARM Comparison

@Michael, I have a general list of requirements, but my intention was not for the community to do my chip section but to try and simplify the process by finding some form of comparison that would allow me to refine the selection process (e.g. table listing peripherals specifications of ALL of the vendors products, indication of the pros/cons of each sub family etc.)

@Alessandro, Thanks for sharing your experiences, I had use a STM32 dev kit and found the lack of quick start information frustrating (as did others online), based what you said I will certainly have another look at it.

@DAB, I possibly was a bit rash in my comments about the C8051. I agree with you that the C8051 has its place, our application has evolved over the last 8 years to a point where the 8051 we are using is bursting at the seams and we would like to add a few more features. Hence look at ARM products.

@Chalie, so true, been caught on that one a couple of times, always read the release notes!

@Kemmi, code migration issues is less of a problem as we intend abandoning the current code and start afresh with C.

On the whole I think the message is get in there and start reading data sheets.

I think if you choose MDK-ARM tool chain from Keil then you will be able to scale your application quite easily.

The tool chain allows for development of ARM7, ARM9, Cortex M0, Cortex M3 from pretty much all the  major vendors with one simple IDE and compiler.

This means you can train yourself up on the tool chain and chop and change between manufacturers devices without the need to repurchase a new tool chain each time.

The tool is the same for all devices, and the only thing you will need to learn are the peripherals on that particular device.

For NXP and ST you will find a range of device libraries that ease the software development on the peripherals with example code for each peripheral.

MDK-ARM is also called the RealView tool suite and is available to down load off the ARM/Keil website.

There is a code restriction on the tool to 32k bytes but other than that it is full feature.

The full tool suite costs about £3k and is available to purchase from Hitex.

http://www.hitex.co.uk/index.php?id=2681

The Keil tool suite is effectively the official tool chain for ARM devices as Keil are owned by ARM. ARM do however support other tool chains such as IAR and GNU so if you have a history with either of these then perhaps this is a better route.

The licensing models for MDK-ARM have changed recently and you can purchase a professional version which now includes support for Ethernet, TCP-IP, email, USB, File Systems etc.

For new designs I suggest you start with Cortex M series cores as they are cheaper and better than the legacy ARM7/9 devices. You can debug with a simulator or via a debugging adapter.

The debugging adapter include ULINK-ME, ULINK2, and ULINK-PRO.

The ULINK-PRO allows for trace debugging.

Best Regards

David Giles

dgiles@hitex.co.uk<mailto:dgiles@hitex.co.uk

I strongly sympathise with your request for a product comparison matrix. I wanted the same more than a year ago.

I did some evaluation back then, against some slightly weird requirements, many of which might not apply to you (I am focused on Open Source hardware).

The advice about tools and examples is very important.

I was moving from an 8-bit AVR.

I chose Cortex-M3 because it provides enough extra performance and improved peripherals without significantly higher cost. I think the new Cortex-M products since last Spring have strengthened the case for it.

When I wrote down my top requirements, and compared the data sheets, the STM32F was a clear winner. I found that surprising as I had expected the products to be very similar. The point is you might find it only takes a couple of days to build a matrix for your product plans and come to a clear conclusion.

Back then, I rated the ST Micro and NXP Cortex-M3's at the top of the list, with STM32F having strengths in ADC and DAC.

If I did it again, I think the STM32F would still win, but I would look very hard at the Atmel Cortex-M3 parts.

If I were in no rush, I'd look at the Cypress PSoC-5 too. It has some very useful features, but more than 6 months after the evaluation kits came out, parts are not slated for 'broad sampling' until August 2011:

http://www.cypress.com/?app=forum&id=2233&rID=44105

It'd also mean working with very new silicon.

Cypress PSoC might actually be an interesting path because Cypress do have 8051-based PSoC now, which might reduce some of the risk.

A thing that might have swung it for a different chip was LeafLabs Maple, which has Open Source tools and unencumbered libraries:

http://leaflabs.com/

This is STM32F, so my path was clear.

It would likely only take a few hours to make an initial matrix using a spreadsheet, but it might not be useful enough unless it is built around your requirements because the information is so multi-dimensional. (That was my feeling after I'd been through the 'I'll find an independent comparison with google, ... here's my requirements, ... here's my analysis' process)