Processor Selection for SoC

Maxim DS89C450 is super fast 51 core,with ISP via com Txd/Rxd

A little bit of clarification (as a H/W designer, I realize that my use of the word embedded is not the same as everyone else on the group)

I need a processor core that I can include within ASIC design (rather than a separate component).

Thanks,

Steven

I don't really know much about which cpu cores are available for such chips, but if you can get it the AVR core would be a good choice for a small low-power embeddable core. It's much faster (for similar power/size/clocks) than 8051, and has much broader tool support. However, if you are looking forward towards the future and bigger cores, there are many ARM cores to choose from. Other embeddable cores with wide tool support are MIPS and ColdFire (certainly ColdFire v1).

An 8051 core is a good choice if the cpu is very much a minor part of the device, and is only there to make the SoC a little more flexible. It is not good at any speed if you want to do any real processing work.

First, decide if an 8051 will still do the task.

This is a topical starting point, for a functional mock-up :

and, for ARM, this pathway should also be looked at

-jg

Can that be included in an ASIC?

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Richard.

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AFAIK, the AVR core is very much designed as a macro for ASICs, and that is the main market for Atmel. Whether or not they will provide the core to others is a very different question - the OP would obviously have to ask Atmel about that.

Of course, I could be wrong about the AVR and ASICs, or perhaps it only applied to the core's early history.

However, these people appear to make ASICs with AVR cores:

Hi Steven,

I work for ARM so my choice is certainly bias towards ARM cores. But the following information might be useful for you.

Faster 8051

8051 IP cores are cheap, but as you can see the performance is limiting. The fastest 8051 IP claimed their Dhrystone DMIPS is 0.1/MHz (but many others are much slower). But you need to be careful as this often require special compiler support or C libraries that make use of the extra features. If using standard 8051 instruction set and features you would get a lower performance.

Due to the lower performance you might end up clocking the core faster and hence getting higher power consumption. And in highend 8051 cores, the register banks are implemented as D-flip-flop rather than SRAM (32

8-bit registers, to allows single cycle execution of instructions). As a result the gate count of the high-end 8051 can be quite large.

16-bit There are not too many commerical 16-bit processors. Most of them are proprietary architecture and therefor the choice of compiler tools are limited. The performance is several times better than 8051 but mostly still less than half of ARM processors. Most of the 16-bit processors has a Dhrystone DMIPS from 0.3/MHz to 0.5/MHz.

The biggest problem you will find with 16-bit core is the 64kbyte memory limitation. Some 16-bit architectures has workaround for this by allow paging or segmentation of memory map but it will reduce the efficiency. If your application requires more than 64kbytes or will expand in the future, switching to ARM would be a better choice.

ARM Cortex-M0 High performance at small size : Dhrystone DMIPS 0.9/MHz. Smaller than most 16-bit cores and very good code density (smaller code size than

16-bit cores and 8-bit cores).

There are large number of choices for C compilers and debug tools, and certainly future proof (e.g. tools, memory expansion). The processor comes with debug features and an integration kit is included to help design.

More details of Cortex-M0 can be found here:

If you want more technical details feel free to contact us directly or let me know. You can try out Cortex-M0 using our Microcontroller Prototyping System (MPS) without any NDA (details on

regards, Joseph

I know that Freescale's now licensing the their 32-bit Coldfire v1 core, and I believe you can also get a license for something in the HC08 line.

--
Rob Gaddi, Highland Technology
Email address is currently out of order

Goto

scroll down to "Processors".

Leo Havmøller.

design.

And don't count the ARC 600 family out as well.

- Higher performance than an an MO at the same same size (1.2 DMIPS/MHz)

- as low as 12,800 gates

- very low power - 0.0012 mW/Mhz on TSMC 90G

- Robust and mature tools support including an overlay manager to take advantage of limited local memory

- Code density on par with an 8051 due to it's 16/32 bit ISA

Drop me a line if you'd like more information.

Andy

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