For 8-lane PCIe lane muxing application a topology with four TMUXHS4412 devices is illustrated. TMUXHS4412 is a passive mux/demux component that does not provide any signal conditioning. If a specific board implementation has too much loss from CPU to PCIe CEM connectors, a signal conditioning device such as linear redriver may be required for best fidelity of the PCIe link. DS160PR421 is a PCIe 4.0 linear redriver with intergrated mux and DS160PR412 is a PCIe 4.0 linear redriver with integrated demux. Both of these devices are pin-to-pin (p2p) compatible with the TMUXHS4412, which allows an easy transition if signal conditioing function is needed to extend the PCIe link reach. Figure 7-3 illustrates p2p passive versus redriver option to implement PCIe lane switching.

Figure 7-3 Pin-to-Pin Passive vs Redriver Option for PCIe Lane Switching