FX12 ethernet resource usage

Do you have a question? Post it now! No Registration Necessary

Translate This Thread From English to

Threaded View
Hi,

I'm working on a design with V4 FX12 and gigabit rgmii PHY.

To me it seemed obvious to use plb_temac and hard_temac (both come with
EDK).  A "small" implementation of these cores (DMA and checksum
offload disabled) uses about 30% of the FX12 area.

For my design this is quite a lot, and I'd prefer to reduce the
resource usage.  At the moment, 100mbit support would be sufficient, as
long as the board and PHY stay the same.  I did not see any options to
disable 10 or 1000 mbit support in the cores, so I suppose they don't
let me save anything here.

Are there leaner alternatives to plb_temac that might work for me?

Regards,
Marc


Re: FX12 ethernet resource usage
Hi,

I'm working on a design with V4 FX12 and gigabit rgmii PHY.

To me it seemed obvious to use plb_temac and hard_temac (both come with
EDK).  A "small" implementation of these cores (DMA and checksum
offload disabled) uses about 30% of the FX12 area.

For my design this is quite a lot, and I'd prefer to reduce the
resource usage.  At the moment, 100mbit support would be sufficient, as
long as the board and PHY stay the same.  I did not see any options to
disable 10 or 1000 mbit support in the cores, so I suppose they don't
let me save anything here.

Are there leaner alternatives to plb_temac that might work for me?

Regards,
Marc


Re: FX12 ethernet resource usage
Quoted text here. Click to load it
Have a look at xapp807: http://www.xilinx.com/bvdocs/appnotes/xapp807.pdf

Uses only a few slices, but you can't use any PLB or OPB components. But
if all you need is Ethernet and nothing else from the PowerPC, this is
probably thew way.

--
My email address is only valid until the end of the month.
Go figure what the address is going to be after that...

Re: FX12 ethernet resource usage

Also take a look at XAPP443.  It uses the embedded TEMAC block and
microblaze in a tri-mode configuration.  It should provide enough
information to get started.  The TEMAC block supports gigabit rgmii, but
this will take some additional logic that may be required for your main
design (and it sounds like your external PHY is already laid out on the
PCB).

Quoted text here. Click to load it



Re: FX12 ethernet resource usage
Quoted text here. Click to load it

plb_temac has a lot of configuration options that drastically affect
the amount of resources required.  If you can use fifo mode (instead
of DMA mode) you will cut it in about half.

Also keep in mind that area usage is pretty meaningless until you fill
the part.  The tools will spread out the logic if the FPGA is sparesely
utilized.

--
Ben Jackson AD7GD
We've slightly trimmed the long signature. Click to see the full one.

Site Timeline