KSZ9893RNXC-TR

The KSZ9893RNXC-TR from Microchip Technology is a 3-port managed Gigabit Ethernet switch in a 64-pin VQFN (8x8mm) exposed pad package. The RNXC denotes the 64-pin VQFN commercial temperature grade package, and -TR denotes tape and reel. The device integrates two 10/100/1000BASE-T copper PHYs (ports 1 and 2) and one configurable RGMII/MII/RMII MAC interface (port 3) for connection to a host processor or SoC. The non-blocking store-and-forward switching fabric provides wire-speed forwarding with a 4096-entry MAC address table and 128KB frame buffer. Advanced managed features include IEEE 802.1Q VLAN with 128 active VLAN groups, 4-queue QoS based on 802.1p priority and DSCP, ACL-based packet filtering, and RSTP/MSTP spanning tree for topology management and ring/linear recovery. EtherGreen power management features include IEEE 802.3az EEE, smart power adjustment based on cable length, and low-power standby modes. Wake-on-LAN enables remote system wakeup. LinkMD cable diagnostics identify cable faults and measure cable length. The flexible management interface supports SPI, I2C, MIIM (MDIO), and in-band management via any switch port, allowing the host to configure and monitor the switch through the most convenient channel.

The KSZ9893RNXC-TR operates through six subsystems: (1) PHY Transceivers: The two integrated 10/100/1000BASE-T PHYs handle the physical layer for copper ports, including 4D-PAM5 encoding (1000BASE-T), MLT-3 (100BASE-TX), and Manchester (10BASE-Te). Auto-negotiation selects the highest common speed and duplex. The PHYs include ADCs, DACs, DSP-based equalizers, echo/NEXT cancellers, and auto-MDIX. (2) MAC Interface: Port 3 provides a configurable RGMII (reduced gigabit MII), MII, or RMII interface to the host processor. RGMII supports 10/100/1000Mbps with only 12 pins (4 data + 4 control + clock + control), while MII/RMII support 10/100Mbps modes. (3) Switching Fabric: The non-blocking store-and-forward architecture receives complete frames into the 128KB frame buffer, performs MAC address lookup in the 4096-entry table, applies VLAN/QoS/ACL rules, and forwards to the destination port(s) at wire speed. (4) VLAN/QoS Engine: Ingress frames are classified into one of 128 active VLANs and assigned to one of 4 priority queues per port. The ACL engine can filter or redirect frames based on Layer 2-4 header fields. (5) Management: The host configures the switch through SPI, I2C, or MIIM registers. In-band management allows the host to send/receive management frames through the data path. Tail tagging enables the host to identify the ingress port of received frames. (6) Power Management: IEEE 802.3az EEE reduces power during idle periods. Smart power adjustment scales PHY power based on cable length. Wake-on-LAN detects magic packets and signals the host.

• Industrial Ethernet switch with 2 copper ports and RGMII uplink to an SoC, VLAN isolation between networks, and RSTP ring topology recovery
• Smart home gateway with 2-port GbE switch connecting WAN and LAN, QoS prioritization for VoIP/video, and Wake-on-LAN for power saving
• Embedded networking module using MII interface to a low-cost MCU, SPI management for configuration, and ACL filtering for network security
• Multi-port IoT edge device with LinkMD cable diagnostics for field troubleshooting, 802.3az EEE for power savings, and jumbo frame support for data transfers