Network

Q：What do emac and phy refer to？

The chip of the data link layer in the Ethernet card is called the MAC controller, and the chip of the physical layer is called the PHY. There are two common usages of emac on this platform:

  1. Emac is connected to phy through MII interface, and phy is connected to network cable through rj45

  2. Emac is connected to switch through RMII interface, switch can be divided into multiple network ports to realize multi-network port function

For detailed information about emac, please refer to https://blog.csdn.net/u012923751/article/details/79667112

Q2: How to add ephy's port drive capability?

riu_r 31 2e //set bit0 to 1 riu_w 31 2e 0x7001 echo swing_100 ±2 > /sys/devices/virtual/mstar/emac0/turndrv //Enhanced port drive capability riu_r 33 42 //View current network drive amplitude

Q3: What if there is a scene with a long network cable (>200m)?

Transmission distance exceeding 100m is beyond specification and reliability cannot be guaranteed, but you can try to limit the speed to 10M.

riu_w 0x31 0x04 0x61
riu_w 0x31 0x00 0x1200
echo max > /sys/class/mstar/emac0/turndrv