My customer reported an issue with DP83822IF: it cannot link with PC's gigabit ethernet port.
The device is connected to MAC through RGMII, 25MHz crystal, pure pin strap configured as: pin RX_ER (RH=6.2K, RL=1.96K), CRS (RH=13K, RL=1.96K), all other strap pins open.
Now, the device can be correctly linked to 10/100M Ethernet, while cannot linked to 10/100/1000M Ethernet. We checked the RGMII interface clock frequency and found it was actually configured as 10Mbps mode (2.5MHz clk frequency) when connected to gigabit ethernet. When connected to 10/100M Ethernet we found the interface clock is configured to 25MHz and the link is correct. Why? how to fix this issue?