1.1 Device Variants

The LAN9645x family is offered in two primary variants:

  • LAN9645xS (Standard): Provides baseline Layer 2 switching functionality suitable for cost-sensitive and simpler designs. These devices support:
    • Unmanaged operation using pin strapping or EEPROM
    • Basic managed operation
    • Static configuration (VLANs, port settings, QoS)
    • Hardware-assisted timing including:
      • End-to-End Transparent Clock
      • IEEE 1588 Precision Time Protocol (PTP, 1-step and 2-step)*
    • Frame Replication and Elimination for Reliability (802.1CB FRER)*

*Requires management from processor

LAN9645xS devices are intended for applications that do not require advanced TSN scheduling or redundancy protocols. While limited runtime control is possible, full feature enablement and dynamic network management require a managed system architecture with host processor and Linux DSA.

  • LAN9645xF (Full Feature): Extends the feature set to include advanced capabilities such as:
    • Time-Sensitive Networking (TSN), including:
      • Time-aware scheduling (TAS)
      • Frame preemption and traffic shaping
    • Audio Video Bridging (AVB) / TSN feature set (802.1Q family)
    • Industrial redundancy protocols:
      • HSR, PRP, and MRP

These advanced capabilities enable deterministic, high-availability networking applications.

Table 1-1. Key Feature Comparison: Standard (S) vs. Full Feature (F) Variants
FeatureSF
Unmanaged✓✓
Managed✓✓
VLAN/QoS✓✓
PTP✓✓
FRER✓✓
TSN✓
AVB✓
HSR✓
PRP✓
MRP✓
Note: Full feature operation requires a managed system architecture using:
  • An external host processor
  • SPI management interface for configuration and control (Linux DSA)
  • A dedicated Network Processor Interface (NPI) port

Dynamic features such as TSN scheduling, redundancy management, and advanced traffic control are only supported in this managed configuration.