General Description

The Realtek RTL9211DS-CG USB (Universal Serial Bus) to SD Express interfaces and SSD (Solid-State Disk) bridge combines a USB device with a PCI Express bus controller and embedded memory.

The RTL9211DS supports USB 3.2 Gen2x1 (Super Speed Plus). It is compatible with USB 3.2 Gen1x1 (Super Speed), USB High Speed, and Full Speed. It can also operate using auxiliary power. Mass storage transactions support both Bulk Only Transfer (BOT) and USB Attached SCSI Protocol (UASP). For USB, it provides up to 10Gbps bandwidth. When the RTL9211DS is connected with an SD Express card, the SD Express port can reach a data transmission speed of 985MB/s. Additionally, the RTL9211DS supports the highest theoretical capacity specification of the 128TB SD card.

The RTL9211DS supports PCIe Gen3x2. For PCIe, it provides up to 16Gbps bandwidth. It has full backward compatibility for PCIe Gen2/Gen1 and 1 lane link width. It supports PCIe 3.0 LTR (Latency Tolerance Reporting). To further reduce power consumption, the RTL9211DS supports link power management (PCIe L1.off and L1.Snooze), PCI MSI (Message Signaled Interrupt) and MSI-X.

The RTL9211DS provides the function of PCIe host. The PCIe host supports NVM Express, which is an interface that allows the host driver to communicate with SSD. The NVMe driver is embedded in customized RAM/Rom/SPI Flash.

The RTL9211DS supports the Type-C connector. It supports dynamically switching power states with NVMe and USB power management for power saving mode. A built-in algorithm balances power consumption and performance.

The RTL9211DS is suitable for multiple market segments and emerging applications, including desktop, mobile, workstation, server, communications platforms, and embedded applications.



  • USB to PCI Express SSD bridge
  • USB to Secure Digital Memory Card bridge
  • Integrated with Type-C connector
  • Supports External Serial Peripheral Interface (SPI) Flash
  • Supports Customized LEDs (includes blinking frequency and duty cycle)
  • Supports UART interface
  • Supports GPIOs/eFUSE
  • Built-in switching regulator (5V to 1V)
  • Built-in LDO (5V to 3.3V)
  • Supports 25MHz crystal clock
  • 68-pin QFN Green package

PCI Express

  • Link speed up to 8GT/s
  • Link width up to 2 lanes
  • Being compatible with PCI Express Gen1/Gen2/Gen3
  • Maximum bandwidth up to 16GT/s
  • Supports LTR (Latency Tolerance Reporting)
  • Supports PCI MSI (Message Signaled Interrupt) and MSI-X
  • Supports PCIe link power management, ASPM L1, CLKREQ, and L1 substate

NVM Express

  • Supports standard command set
  • Dynamic power state translation
  • Strong Error handing and recovery
  • Supports all command set of NVM Express SCSI Translation (e.g., Unmap, Security protocol in/out …)
  • Supports Security Send and Receive
  • Supports SMART/Health information

SD Express

  • Realtek Card Reader supports backward compatibility with the speed of UHS-I (Ultra High Speed-I)
  • Supports SD Express (Gen3 single lane interface, NVMe 1.3)


  • Link bandwidth up to 10Gbps
  • Compatible with Full Speed/High Speed/Super Speed/Super Speed Plus
  • Supports Bulk Only Transfer (BOT) and USB Attached SCSI (UAS) protocol
  • Supports USB link power management
  • Supports SCSI command that translation to NVM Express


  • Supports Cable Orientation Detection


  • USB 3.2 Gen2x1 SS+/SS/HS with PCIE SSD mass storage or SD Express memory card on motherboard, notebook, Embedded or mobile phone system supporting BOT and UASP mass storage specifications.