phy芯片设置百兆全双工自协商连接千兆交换机时网络ping不通，连接百兆交换机正常 P1连接千兆交换机phy寄存器 P2连接百兆交换机寄存器 P3主控关键寄存器
Translation:
When the Ethernet PHY chip is set to 100M full-duplex auto-negotiation and connected to a gigabit switch, the network ping fails, but it works normally when connected to a 100M switch. P1 connects to the gigabit switch phy register. P2 connects to the 100M switch register. P3 master control key register.
