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LEON processor core

I'm wondering why there are so few messages about LEON [1] in this group. LEON looks like a very solid design (used by the ESA) and it is available in a GPL version. Could be a vendor independent replacement of NIOS/MicroBlaze with a path to an ASIC. The configuration is done via a simple Tcl/Tk script and the Makefile contains several targets. Works out-of-the-box for available tragets. Adaption to a new FPGA board [2] took me a few (some) hours - not so bad.

What's your experience?

Martin

[1]
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[2]
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Reply to
Martin Schoeberl
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"Martin Schoeberl" schrieb im Newsbeitrag news:441451f8$0$11610$ snipped-for-privacy@tunews.univie.ac.at...

2 hours is correct, that what it usually takes to port LEON to new hardware.

and the best thing is the LEON system can run FULL MMU enabled linux in spartan3 or any other low cost FPGA!

Antti

Reply to
Antti Lukats

Is it possible to use it without SRAM and only with SDRAM ?

Reply to
Jerome

"Jerome" schrieb im Newsbeitrag news:44145fdd$0$13024$ snipped-for-privacy@news.free.fr...

well you need some initialized memory unless you are loading the sdram over jtag debugger

basically, yes if you have means to load your application or bootloader into sdram there si no need for any other memories

antti

Reply to
Antti Lukats

its got its own ( yahoo based ) news group.

And yes, its pretty cool.

Reply to
ziggy

Ok but my concern is about R/W cycles assuming i want to use SDRAM for code execution or data storage. Acessing SRAM is only 2 cycles (adr / data ) But for SDRAM , event with smart sdram controller , it will take more , no ?

Reply to
Jerome

"Jerome" schrieb im Newsbeitrag news:44147254$0$13020$ snipped-for-privacy@news.free.fr...

thats almost always so that ext(sdram) accesses are way slower cache helps to re-gain some cycles and improves performance

but as sw is getting larger and doesnt fit into onchip memory so there are no options to use of sdram so if you can use BRAMs for cache only

antti

Reply to
Antti Lukats

I keep meaning to try it, seeing as I share my first name with it. 8-)

Leon

Reply to
Leon

Can you put the initial bits into the cache? (and setup the extra bits for the cache to say they are valid.)

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Reply to
Hal Murray

Hi,

you forgot to mention the MP (multiprocessor) support in LEON3 (up to 4 microprocessors). Of course, you need to use the eCos version available for this MP system. I tested it 6 months ago and it works great. I think that now the support will be better than 6 months ago ;)

Regards,

Ivan

Mart> I'm wondering why there are so few messages about LEON [1]

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Reply to
Ivan

than you are way smarter than me ;-)

Do you know the minimum amount of RAM one needs to run Linux or eCos?

Martin

Reply to
Martin Schoeberl

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