2.5Gbps Ethernet PCS IP Core

The Lattice 2.5 Gbps Ethernet PCS IP core implements the state machine functions for the physical coding sublayer (PCS) described in the IEEE 802.3z (1000BaseX) specification. Note that the IEEE specification describes a PCS that operates at 1Gbps. Therefore, this 2.5G PCS IP core is non-standard with respect to the IEEE specification.

The two major non-compliances are data rate (2.5 Gbps instead of 1 Gbps) and GMII data bus width (16 bits instead of 8 bits).

This PCS IP core was specifically developed to operate with the Lattice 2.5 Gbps MAC IP core. The Lattice 2.5G PCS and MAC IP cores are 100% compatible and can be used to create a full PHY/MAC Ethernet data path that operates at 2.5 Gbps.

This document describes the 2.5 Gbps Ethernet PCS IP core’s operation, and provides instructions for generating the core through the Lattice IPexpress™ tool, and for instantiating, synthesizing, and simulating the core.

The 2.5 Gbps Ethernet PCS IP core converts GMII frames into 8-bit code groups in both transmit and receive directions and performs auto-negotiation with a link partner as described in IEEE 802.3z specification.


  • Implements the transmit, receive, and auto-negotiation functions of the IEEE 802.3z specification
  • 16-bit GMII interface operating at 156.25 MHz (2.5 Gbps)
  • 8-bit code-group interface operating at 312.5 MHz (2.5 Gbps)
  • Parallel signal interface for control and status management

The 2.5Gbps Ethernet PCS IP Core is available as an IPexpress user configurable IP core, which allows the configuration of the IP and generation of a netlist and simulation file for use in designs. Please note that generating a bitstream may be prevented or the bitstream may have time logic present unless a license for the IP is purchased.

Block Diagram

Performance and Size

Parameters LUTs sysMEM EBRs Registers
Data Path Width: 16 600 0 900

1. Performance and utilization data are generated targeting an LFE3-17EA-8FTN256C device using Lattice Diamond 1.3 software and Synopsys Synplify Pro for Lattice E-2011.03L. Performance may vary when using a different software version or targeting a different device density or speed grade within the LatticeECP3 family.

Ordering Information

Family Part Number
LatticeECP3 2PT5-PCS-E3-U

IP Version: 1.0.

Evaluate: To download a full evaluation version of this IP, go to the IPexpress tool and click the IP Server button in the toolbar. All LatticeCORE IP cores and modules available for download will be visible. For more information on viewing/downloading IP please read the IP Express Quick Start Guide.

Purchase: To purchase the IP Core, please contact your local Lattice Sales Office. 


Quick Reference
2.5Gbps Ethernet PCS IP Core User's Guide
IPUG99 01.0 3/28/2012 PDF 2.2 MB