Is the Microblaze soft cpu better than the Cortex M3 soft cpu

Question

Is the Microblaze soft cpu better than the Cortex M3 soft cpu in terms of functionality?

Given all the buzz about the ARM based processors, I was wondering if to implement an ARM processor on my FPGA or if I should stick to the Microblaze that comes with it.

Is there any major difference in terms of performance or functionality that I should consider?

From what I gathered from the responses: Microblaze is a better soft cpu than it's ARM counterparts. Therefore it is better for FPGA use. Thanks all. — , Feb 17 '11 at 17:35
Note that the advantage - Xilinx designed - is also the disadvantage. The Microblaze is only officially available for Xilinx chips. There are clones of both platforms, however, as well as independent designs. — Yann Vernier, Apr 12 '11 at 12:14
Are there any designs for the ARM cortex 9 for Xilinx chips? — , Apr 12 '11 at 19:41

score 8 · Accepted Answer · answered Feb 16 '11 at 19:52

8

The two major points are:

The Microblaze is a well supported soft core. Many other IP designs are made to interface with it. ARM is popular, but you'll have less support available, especially from Xilinx, who designed the Microblaze.
Using an ARM core will let you use compilers (and code) designed for the ARM architecture, which is desirable because (according to my totally unbased guess) more code is written for ARM than for Microblaze.

I'm not familiar enough with either processor to make further comparisons without a list of priorities. What do you value in this processor?

answered Feb 16 '11 at 19:52

Kevin Vermeer

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My priorities are: 1) Performance, using less logic cells is better 2) Community, What I'm trying to do is hard enough without support from a community. 3) Flexability, the ease at which new "instructions" can be added. I'm using a Spartan 3E with 500K gates (10K cells). – Feb 17 '11 at 14:22
You contradict yourself. You can't have one priority that says "performance" and "minimal logic cells". Those are two, competing, properties. – Marcus Müller May 26 '16 at 22:01
really, a Spartan 3E? That thing is **old**. I doubt ARM sells an Cortex M3 IP core that runs on that; where did you find that option? – Marcus Müller May 26 '16 at 22:03

score 4 · Answer 2 · answered Feb 16 '11 at 23:49

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A 'standard' CPU core will use a lot more resources in an FPGA than one specifically targetted at a particular FPGA.

answered Feb 16 '11 at 23:49

mikeselectricstuff

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score 3 · Answer 3 · answered Feb 16 '11 at 19:57

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The Microblaze processor has the advantage that it was designed for use on Xilinx FPGAs and will therefore offer more performance than the ARM. It also has additional features such as hardware floating-point operations.

answered Feb 16 '11 at 19:57

Leon Heller

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Does an ARM soft core not give you hardware floating-point operations? – Kevin Vermeer Feb 16 '11 at 20:37
A Cortex-M3 won't! – Leon Heller Feb 16 '11 at 21:59
Would it be too complicated to provide a bus to an FPGA multiplier? – tyblu Feb 17 '11 at 01:39
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The ARM has a multiplier. There is a lot more to floating-point than that. – Leon Heller Feb 17 '11 at 07:07

score 0 · Answer 4 · answered May 26 '16 at 21:59

regarding functionality MB vs ARM Cortex-M3, basically the Cortex-M3 contains a ARMv7-M CPU and that means it's based on ARMv6-M. Check out some screenshots showing off mainstream features. MB will definitely be better integrated on Xilinx FPGA fabric and its 'in the field' since many years. For more info on MB, search UG081 - MicroBlaze Processor Reference Guide.

Kind regards

Is the Microblaze soft cpu better than the Cortex M3 soft cpu

4 Answers4