100Mbps ethernet core

I have an Avnet development board with a V2P20 on it. It came with a reference design that has Linux running on the PPC, and uses the OBP_EMAC core to talk to a PHY on the development board. The demo include a simple web sever, and it works.

The Linux distribution came from

and has an old version of a driver for the Xilinx EMAC core. The driver was written by MontaVista.

There is a newer version of the driver available in the bitkeeper repository for the PPC version of the kernel. Look at

for information on how to get the kernel, and other good info. Also check out

John McCaskill

could you acheive 100Mbps bandwidth ?

snipped-for-privacy@fastertechnology.com wrote:

of

Using the Avnet board with the Avnet bitfile and Linux, the sustained bandwidth that I was able to achieve was less than 2MB/s. In addition to using the OPB_EMAC core instead of the PLB_EMAC core, the Avnet bitfile also runs Linux out of external SDRAM memory connected via the OPB bus. So I don't know which is the bottleneck, but I would guess the memory is probably the bigger factor. I will probably be doing some tests soon to try to find the source of the problem.

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My real email is akamail.com@dclark (or something like that).

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We have not measured the speed of the 10/100 EMAC. There are a number of reasons to support the slower speeds that Duane Clark mentioned:

The EMAC core is on the OPB bus, and does not use the DMA engine in the IPIF. The processor has to copy the data between the core and memory. As the reference design is supplied, the PPC is only configured to run at 66MHz. The memory used in the reference design is on the OPB bus. The OPB bus has burst mode turned off. (At first glance, it does not look like the OPB memory interface works with burst mode turned on).

My guess is that the OPB EMAC was used because a real version of the core is supplied with the EDK. All of the PLB EMAC cores are evaluation versions. You can use them in a design, but they turn themselves off after about 12 hours.

John McCaskill

So you chose anonymity, I can only guess that you have some relation to the Avnet board/project from your comments. In any case, I will add a comment that the board and project as provided by Avnet are quite impressive in my opinion. And at the price, they simply cannot be beat.

Actually, the OPB_EMAC core supplied with EDK is also an evaluation version, with the same timeout limitation.

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My real email is akamail.com@dclark (or something like that).

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to ^^^^^^^??????? The email I post with is real, it just gets more heavily filtered.

beat.

I agree, that is why we use them. My list above is just a list of what to upgrade if one wants to speed up the design.

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John McCaskill (Really)

My apologies. Rereading things, I see I just didn't read carefully.

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My real email is akamail.com@dclark (or something like that).