MDIO interface

[EthMcStone]

Hi everyone!
I'm a student from germany and i use this core in a student project
for a xilinx SP605-Board. This ETH-Core works great, thanks for all
your work.
Now i'm trying to use the MDIO-interface to configurate the ethernet
chip (Marvell Alaska 88E1111). But i don't understand the system how
it works. Where can i set the "divider" of the clk_gen module? All
signals are specified in the reg_int.v, but that's it. I'm using the
Xilinx ISE 13.2 and XST only writes "Unused signal", so the eth_miim
module is just dead code. Or did i miss a file? Do i have to use the
host-system?
maybe you can explain your proceeding or what i have to do. I read
about the MDIO spec, thats not the point, i just don't know how i use
your core.
So thanks for your help, you post ince 10 years, thats realy rare. I
hope my english is not as bad as my teacher in school always told
me ;)
greetings
MacStone

[gao jon]

MacStone,

 

It's great to hear it works. I hope you enjoy the process to make it work.

 

I did not design the MDC interface by my own. I remember I ported from another project. But I cannot clearly remember which project now. You can go to Opencore website to check if there is any MDC project overthere.

 

The algorithm of MDC interface is similar to I2C interface.  The MDC logic looks like a I2C controller. If you have experience with I2C, I will be easier to understand it. the Reg_int.v designed a general host interface. Yes, it's easier to use a host to access MDC interface. Another alternative is using a statemachine to emulate the host, it should work but a little trivial. FPGA is not effcient to to that. I recommend you to instantiate a Microblaze or Picoblaze CPU inside your eval board. You could learn more about a small SOC design.

 

Good luck and enjoy it.

 

Jon.

[EthMcStone]

Hi Jon.
Did you ever see a design with your core which used the MDIO-
Interface? It looks for me as it is unused.
Maybe i can spend some time to fix it, maybe someone else did it
already.
regards
EthMac(Stone)

[Chuck Handley]

Hi MacStone,
The opencores project where the MDIO code originated is the 10/100
Ethernet mac:
http://opencores.org/project,ethmac
In the docs folder, you will find some information describing its
design and use.

I've used it with the SMSC LAN8710 and the Micrel KSZ8001, and it
works well.

Regards,
Chuck

[gao jon]

Chuck,

 

Thank you to point out the origin of MDIO code.

 

EthMac,

MDIO is a standalone functionality. Most of PHYs can work without MDIO configuration. If you want to use it, you can refer to spec of 10/100 ethernet MAC. I don't think you need to do some modification to make it working. It should work now.

 

 

Thanks,

Jon

 

From: Chuck Handley <netc...@gmail.com>
To: opencores-tri-mode eth MAC <opencores-tri...@googlegroups.com>

[EthMcStone]

sorry guys, i didn't receive an e-mail, so i didn't notice your posts.
i found this project allready but thanks for the link. Actually I'm
writing a simple FSM to controll only the MIIM/MDIO, but i had to
modify some of the files: MAC_top.v and reg_int.v. So i seperated the
MDIO-Files to write my own VHDL-Wrapper for my bus.
THanks for the help.
EthMacStone

[tamirci]

Hi EthMcStone,

You indicate this core is working. Could you please provide TX side wrapper?

regards

29 Kasım 2011 Salı 19:49:17 UTC+2 tarihinde EthMcStone yazdı: