Hi guys, A problem concering broadcom PHY 5461 loopback mode(internal loopback).from mac ----phy----mac the phy works well on 100M loopback, but cannot works in 1000M mode,i am sure regiser setting are write correctly.
A strange problem is : when i ping from another swith(not in loopback mode), 5461phy can received data correctly , and mac connected with 5461 return arp requset to phy, but, 5461 cannot transmitted the data,using oscilliscope, i can see the data on 5461 TX pins, it means mac succefully transmit data to 5461,
now we consider loopback again,since we can receive data, and mac can transmit data, why the phy cannot loop the data back to MAC
any advice from you would be great help!