M88MX5891 is a Type 3 Compute Express Link® (CXL®) Memory eXpander Controller (MXC), which enables high-speed and low-latency interconnect between the CPU and CXL®-based devices.

The MXC integrates a CXL® controller, a DDR controller, a RISC-V microprocessor, and rich peripheral interfaces such as SMBus, I3C/I²C, and SPI in a single chip. It is compliant with JEDEC DDR4/DDR5 standards and CXL® 2.0/PCIe® 5.0 specifications.

As the key component for memory expansion and pooling, the MXC is intended for use in add-in cards (AICs) and EDSFF memory modules, enabling dramatically scaling of memory capacity and bandwidth to meet the ever-growing demand from HPC and AI applications.



  • CXL® Type 3 Memory eXpander Controller
    • Integrated CXL® controller, DDR controller and RISC-V micro-processor
    • On-chip PVT sensor
    • SMBus, I3C/I²C, and SPI interfaces
    • Package: 767-ball FCCSP
  • CXL® Controller
    • Compliant with CXL® 1.1 and CXL® 2.0 RAS specifications, supporting CXL®.mem and CXL®.io protocols
    • Designed based on PCIe® 5.0 interface, supporting up to 32 GT/s data rate (x8 lanes)
    • Rich RAS features
  • DDR Controller
    • Compliant with JEDEC DDR4/DDR5 standards
    • Support DDR4/DDR5 UDIMM/RDIMM and DRAM on-board
    • Support up to DDR4-3200 and DDR5-5600
    • Low power consumption
    • Optimized DDR I/O equalization and programmable I/O impedance


  • Add-in card or EDSFF memory module for memory expansion, memory pooling, etc.
  • AI, machine learning, cloud infrastructure, high-performance computing, etc.