75Mhz Spartan3e microblaze

you should try using xplorer. Keep the MB cache size to < 8K.

/Siva

Hi Urban,

It also depends on what setting you put on MicroBlaze and how your system looks like.

If you post your settings for Microblaze from the .mhs file, I can tell you if there is anything you should change.

Göran Bilski

hi

well thanks for the answers. i tried a design with no cach and with data and instruction cache (2k). with multiple iterations i meant that i was using xplorer. here ist the system.mhs file (with cach) and the system.ucf file

thanks urban

One of the problems with OPB is that the more peripherals you add the slower it goes. All of the control signals data returns from modules etc are ORed together. There are ways to improve module response to clock e.g. pipelining the return of data. It is worth looked at the results in timing analyser to identify problem modules and see if you can do anything to improve the speed of them.

On the brute force approach try using multiple place and route. Option can be set in the Placement options in ISE. Also playing with synthesiser switches - especially hierarchy settings may also help.

John Adair Enterpo> hi

John Adair schrieb:

John, the OP was already doing multi-pass optimization with the xplorer script and he has pretty much minimal bare bones system so he should be able to meet 65MHz+ timing

well there is almost another option

ethernet lite requires only 50mhz clock frequency - unfortunatly Petalogix has only released the binary demo with the ethernet lite uclinux drivers (GPL licensed ASFAIK) so the only option currently is really getting the system clock freq above 65 and use full ethernet core

Antti

hi

well thanks for all the answers so far. i 'm still trying to get some more speed out of edk. well as said before i'm not doing anything fancy. just straight forward stuff and i was wondering what good the ethernet core is if i can't get it to synthesize with more than 59 MHz. i have also tried to export it to ise. i mean there must be a trick somewhere or has nobody used microblaze with ethernet in a spartan 3e yet? any suggestions would be very helpful

thanks urban

I was pretty sure someone recently had just that running on the spartan-3e starter board. Uclinux with networking and I think it was microblaze. Look in the archives, like in the last 1-2 months.

-Dave

--
David Ashley                http://www.xdr.com/dash
Embedded linux, device drivers, system architecture

David Ashley schrieb:

David

you are right there is s3e500 uclinux design from

but they use ethernet lite that has only 50mhzrequirement. unfrotunatly petalogix is not releasing the ethernet lite driver source codes (GPL !) so other can not use the ethernet lite core with uclinux yet.

Antti

uClinux does run on the Spartan-3e starter board. If the design doesn't reach at least 65 MHz you can still use the Ethernet core at 10 MBit -

6.5 MHz bus clock is sufficient. Make sure half-/full-duplex and speed is set correctly, because auto negotiation doesn't seem to work reliably.

Regards, Andreas

Andreas Hofmann schrieb:

actually the ethernetlite uclinux driver was submitted to cvs yesterday, so its also possible to use the ethernet lite with 100M (and

50MHz system clock)

Antti