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Altera_Forum
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8 years ago

About problem with using EMAC splitter and GMII_TO_RGMII

Hello,

I am newer.

One of EMAC in HPS is being used by the construction with the pin of FPGA.

The design of the hardware is reference of the following site.

(https://rocketboards.org/foswiki/view/projects/cyclonevrgmiiexampledesign)

When I tried to do ping test by using WindowsPC, I confirmed it worked fine in 10Mbps(Full/Half), 1000Mbps.

But It failed only at 100Mbs.

So I have investigated now, and I did following procedure,

  • Set the ctrl register of System Manager(0xFFD08060) to “1” (RGMII).

It works fine. It passes ping test at 10Mbps, 100Mbps and 1000Mbps.

But I do not understand why?

I think that EMAC may be connected to GMII_TO_RGMII IP package.

So the value of ctrl register of System Manager(0xFFD08060) shall be “0”(GMII).

Please tell me why?

Best Regards,

H.Wada
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