TMUXHS4412: PCIe x4 multiplexer design

Hi,

I am designing a motherboard which requires 2 PCIeX4 connector, the standard PCIex4 connector(SAMTEC PCIE-064-02-S-D-RA) and M.2 KeyM connector(Molex 1-2199230-6). but my CPU has only x4 PCIe_TX and 4x PCIe_RX lanes.

I was thinking of using a dual PCIe mux chip like TI TMUXHS44128 for TX and RX lines and for reference clock I was planning to use a clock mux. Can you please recommend a design by which we can do this?

we dont need to switch between the connectors dynamically, we only have to power-off the board switch the lanes to second connector and power on the board

can you pelase share any reference design or evaluation board for this purpose of our testing or any other part that we can use?

Thanks,

R.Rohith yadav