does TX2 support X4 lane endpoint device via its PCI-Express x4 slot~

does TX2 support X4 lane endpoint device via its PCI-Express x4 slot~

The TX2’s PCIe controller acts as a root complex, so it can be connected to switches or endpoint devices. The TX2’s PCIe controller cannot act as an endpoint itself. To accomplish that, you would need to add a non-transparent (NT) switch to the topology.

Please consult the Jetson TX2 Module Datasheet and OEM Design Guide for details pertaining to the PCIe controllers.
Here’s some of the specifications of the x4 port:

  • x4 lane configurations
    • Supports x4, x2, and x1 configurations with conventional PCIe interface
    • Supports lane reversal for x4 and lane flipping for x2 and x1
    • Supports polarity inversion
    • Supports Gen1 and Gen2 link speed
    • Supports dynamic link speed and lane width change

    So according to this explanation, Is it possible to reverse
    [PCIe#0 Lane0]
    J2 B14 <-- PETp0 – PEX_TX1_P
    J2 B15 <-- PETn0 – PEX_TX1_N
    J2 A16 <-- PERp0 – PEX_RX1_P
    J2 A17 <-- PERn0 – PEX_RX1_N

    [PCIe#0 Lane1]
    J2 B19 <-- PETp1 – PEX_TX2_P
    J2 B20 <-- PETn1 – PEX_TX2_N
    J2 A21 <-- PERp1 – PEX_RX2_P
    J2 A22 <-- PERn1 – PEX_RX2_N

    [PCIe#0 Lane2]
    J2 B23 <-- PETp2 – PEX_TX3_P
    J2 B24 <-- PETn2 – PEX_TX3_N
    J2 A25 <-- PERp2 – PEX_RX3_P
    J2 A26 <-- PERn2 – PEX_RX3_N

    [PCIe#0 Lane3]
    J2 B27 <-- PETp3 – PEX_TX4_P
    J2 B28 <-- PETn3 – PEX_TX4_N
    J2 A29 <-- PERp3 – PEX_RX4_P
    J2 A30 <-- PERn3 – PEX_RX4_N

    Thanks.

    Hi, not all reverse are supported, please check pinmux sheet for it.