About problem with using EMAC splitter and GMII_TO_RGMII
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