U31X2-PCIE4XG321 | 4-port Type-C USB 3.2 to PCI Express x4 Gen 3 Host Card | Asmedia ASM3142


Dual Channel 4-port (2-port x 2) USB 3.1 Gen 2 (10Gbps) to PCI Express x4 Host Card

2-port (Type-C & Std-A)USB 3.1 to PCI Express x4 (x2 mode) Gen 3 Host Card w/PD 2.0


  • Host Bus: PCIe x4 Gen 3 (32Gbps)
    • Compliant with PCI Express Base Specification Revision 3.0
  • Dual independent USB 3.1 Host Controllers  (Asmedia ASM3142, USB IF TID 5080000010)
    • Compliant with Universal Serial Bus 3.1 Specification Revision 1.0
    • Compliant with Intel’s eXtensible Host Controller Interface (xHCI) specification Revision 1.1
  • Four USB 3 Cable Ports (Type-C Receptacle, USB IF TID 5200000315)
    • Provides USB 3.x cable port lock mechanism


The U31X2-PCIE4XG321 is a Dual Channel 4-port (Type-C) USB 3.1 Gen 2 (10Gbps) to PCI Express x4 Gen 3 Host Adapter.

U31X2-PCIE4XG321 is designed with Two key components.

  • 12-Lane, 5-Port PCI Express Gen 3 Switch.
  • PCI Express to USB 3.1 Single Chip Host Controller  (Asmedia ASM3142, USB IF TID 5080000010)

Utilizing the standard PCI Express Switch, the 12-Lane/5-Port PCI Express Switch provides the most efficient fan-out solution for integrating four PCI Express to USB 3.1 Gen 2 Single Chip Host controllers into a small board design. Each USB 3.1 to PCI Express Single Chip Host controller takes advantages of 10 Gbps burst rate of 4-lane PCI Express bus in both directions and is fully compliant with PCI Express Base specification r3.0. This solution provides full PCI Express and USB 3.1 functionality and performance.

Technical Specifications

Primary PCI Express
  • Standards compliant
    • PCI Express Base Specification r3.0 (compatible with PCIe r1.0a/1.1 & 2.0)
    • PCI Power Management Spec r1.2
    • Microsoft Windows Logo Compliant
    • Supports Access Control Services
    • Dynamic Link-width control
    • Dynamic SerDes speed control
  • High Performance
    • Non-Blocking switch fabric
    • Full line rate on all Ports
    • Cut-Thru with 154ns max packet latency
    • 2KB max payload size
  • PCI Express Power Management
    • Link power management states: L0, L0s, L1, L2/L3 Ready, and L3
    • Device states: D0 and D3hot
  • Quality of Service (QoS) support
    • Traffic Class Queuing
    • Eight Traffic Classes per Port
    • Weighted Round-Robin source port arbitration
Secondary PCI Express
  • Support PCI Express Gen2x2 or Gen3x1
  • Up to 10Gbps bandwidth performance with low latency
  • Support PCI Express Link power management
  • Compliant with PCI Express Base 3.0 Specification
  • Compliant with PCI Express card Electromechanical 2.0 specification
  • Compliant with PCI Express Mini Card Electromechanical 1.2 specification
  • Compliant with Express Card Standard Revision 2.0
  • Compliant with PCI Bus Power Management Interface Specification Revision 1.2
  • Compliant with PCI Local Bus Specification Revision 3.0
  • Support overclocking capability on PCI Express interface
USB Features
  • One Channel support two ports of USB 3.1
  • Up to USB 3.1 Gen 2 10Gbps
  • Compliant with Universal Serial Bus 3.1 Specification Revision 1.0
  • Compliant with Universal Serial Bus Specification Revision 2.0
  • Compliant with USB Attached SCSI Protocol Revision 1.0
  • Support Multiple INs function
  • Support USB 3.1 and USB 2.0 Link Power Management
  • Support Control, Bulk, Stream, Interrupt, Isochronous transfer type
  • Support independent port power control
  • Support overcurrent detection
  • Integrate Spread Spectrum Controller for USB 3.1 interface
  • Backward compatible with Legacy USB function and device
  • Support the Debugport
Number of USB Ports Four independent USB 3 Cable Ports
(Type-C Receptacle)
  • Type C Receptacle, USB IF TID 5200000315
  • Std-A type Receptacle, USB IF TID 360000006
USB Bus Power Input
  • USB bus power may from the following source (A or B): 

    • A. From PCIe 12V (Step-Down)
    • B. From Power Connector (IDE 4-pin or SATA 15-pin)