Can NVHS for PCIE x8 of AGX Xavier change from X8(NVHS0_TX[0:7]_N/P,NVHS0_SLVS_RX[0:7]_N/P ) to PCIE X4(NVHS0_TX[0:3]_N/P,NVHS0_SLVS_RX[0:3]) ? How to configure by software ？
Looking forward to your reply！
No, Xavier series platform only support the configuration same as the devkit.
PCIe x8 also supports x4 devices.
If AGX Xavier is as endpoint，only use PCIE X4(connect NVHS0_TX[0:3]_N/P,NVHS0_SLVS_RX[0:3],not connect NVHS0_TX[4:7]_N/P,NVHS0_SLVS_RX[4:7]).Can Xavier support this situation ？
Yes, it will work on Xavier
Does it means that it can not change from X8 to X4 directly by software configuration(EP or RC)?
Yes, the configuration should follow the devkit. If devkit is x8, then configuration on your board is x8.