Sorry for my limited knowledge and limited English skill.
Quite a few companies are trying to sell their Cortex-M3 MCU to our company. Texas Instruments' technical sales engineer visited our office, to promote the Stellaris Cortex-M3. Several local distributors also contacted us for promoting other Cortex-M3 MCU, like STM32.
In the past few days, I noticed that, ST is promoting their STM32F4 series. And the price of STM32F4-Discovery kit is only around USD 27, unbelievable cheap to me. So I did some quick study about it. Several Simplified Chinese articles talked about the success of STM32 MCU, and the intense competition of the Cortex-M4 market. They also concluded that, the age of Cortex-M4 is coming.
I am trying to introduce the Fujitsu 16FX to our company, which is good in price and features. (don't want to deal with outdate MCUs anymore.) But Cortex-Mx is more general, and has a lot of resource to use. I heard that Cortex-M4 is 10% expensive than Cortex-M3, but with powerful DSP and FPU.
I almost don't know anything about DSP/FPU and any Assembly language. My quick study of Cortex-M4 shows that, the FPU performance of STM32F4 is slower than expected, and compilers do not support the FPU well, so, to utilize the FPU, users need to use Assembly language. Besides, if users use floating point in the Interrupt Service Routine, some extra efforts has to be done to deal with the Context Switching, this slowdown the interrupt performance, add extra complexity.
How do you think about Cortex-M4, and would you start to evaluate it?
I would evaluate it if I had, or expected to have, projects that require that level of performance.
It sounds like Cortex-M3 (maybe even M0/M1?) is adequate for your requirements, and it's quite enough for you to get "up to speed" on that - so why over-burden yourself with stuff you don't (yet) need?
Once you've got used to M3, the "step-up" to M4 - should you ever need it - should be relatively easy.
"I am trying to introduce the Fujitsu 16FX to our company"
Why would you want to get tied-in to a proprietary, single-source architecture?
I think these days it's not so difficult to decouple the source code from the choice of the CPU core. In my experience, the transition from ARM7TDMI to ColdFire and then to Cortex-M3 was not painful at all. Keep in mind that ColdFire is big endian. Transition between 16-bit and 32-bit CPU could be more tricky, but with some care writing portable code for them shouldn't be too difficult either.
Wasn't the 8031 single sourced by Intel when it first came out?
I'd better have words with them and tell them how crazy they were to get tied into that single sourced architecture those 30+ years ago.
If only they'd have held off until ARM was available, my task of supporting their still live projects would have been so much easier!
Almost certainly - that was the way it was back then.
If I could tell in advance which technologies/products are going to live long & prosper, and which will die a death - then I'd be a very rich man!