This guide is meant to explain how to upgrade the the ClearFog Pro to support both CN9130 SOM and A388 SOM.
Assembly of 25MHz reference clocks for Ethernet Switch and PHY
Dis-/Assemble the components from table below:
# | RefDes | Action | Comments |
1 | R140 | Remove | resistor 220Ω |
2 | R141 | Remove | resistor 499Ω |
3 | C52, C55 | Add | capacitor 22pF |
4 | Y1 | Add | crystal 25MHz |
5 | R138 | Remove | resistor 220Ω |
6 | R139 | Remove | resistor 499Ω |
7 | C154, C158 | Add | capacitor 22pF |
8 | Y2 | Add | crystal 25MHz |
The components locations are marked green / red in the pictures below:
Components side
Print Side
Impact
CN9130 SoM does not provide a 25MHz reference clock output, The changes outlined disconnect the SoM reference clock signal and replace it with crystals for both ethernet switch and port 6 phy.