BCM56640B0KFSBG

Overview

The BCM56640B0KFSBG is a Layer 3 Ethernet Switch ASIC from the Broadcom StrataXGS Tomahawk series. It provides a switching capacity of 3.2 Tbps and integrates 128 lanes of 25 Gbps SerDes. The chip supports flexible port configurations, including 32 ports of 100 GbE, 64 ports of 40/50 GbE, or 128 ports of 25 GbE. It features a configurable pipeline with port-to-port latency under 400 ns. Key processing capabilities include FleXGS high-density flow handling, Smart-Table, Smart-Hash, and Smart-Buffer technologies.

Feature Summary

• Hardware acceleration for VXLAN, NVGRE, MPLS, and SPB overlay tunneling protocols to support cloud network virtualization.
• Integration of BroadView telemetry for real-time flow statistics, link health monitoring, congestion detection, and packet tracing.
• Support for RoCE and RoCEv2 protocols to optimize performance in storage and AI training networks.
• Smart-Hash technology designed to prevent hash polarization in Leaf-Spine topologies.

Applications

• Data Center Top-of-Rack (ToR) switches connecting 25G servers.
• Leaf and Spine layer switches utilizing 100G uplinks.
• High-performance storage area networks requiring RDMA support.
• AI and machine learning cluster interconnects.

Procurement Notes

Verify the specific silicon stepping and package revision against the manufacturer's latest documentation before procurement. Confirm that the required SDK version supports the intended protocol features, such as RoCEv2, as implementation details may vary by software release. Ensure compatibility with the host system's PCB design requirements for large FBGA packages.

Selection Notes

Select this component for designs requiring high-density 25G connectivity or scalable 100G aggregation within a single chassis. Evaluate the thermal management requirements associated with the large pin-count FBGA package. Consider the availability of development tools and reference designs provided by Broadcom to accelerate the integration of the FleXGS architecture into the target network operating system.

Part Context

This part belongs to the StrataXGS Tomahawk generation, representing an early adoption of native 25G SerDes technology. It serves as a foundational switch fabric for modern data center architectures transitioning from 10G to 100G speeds. The B0KFSBG suffix indicates the specific silicon step and environmental compliance status within the broader BCM56640 product family.

Replacement Considerations

Direct functional replacements are not explicitly listed in public documentation. Upgrades typically involve moving to newer generations such as the BCM56771 series for higher throughput. Designers should consult Broadcom engineering for migration strategies when replacing legacy components with current Tomahawk variants.