LPDDR5X IBIS-AMI with Clock Forwarding

This example shows how to use Signal Integrity Toolbox™ for MATLAB® to analyze a LPDDR5X interface with the IBIS-AMI feature, clock forwarding, enabled for analysis of system margins. IBIS BIRD 204, "DQ_DQS GetWave Flow for Clock Forwarding Modeling," adds the ability to pass in an external clock signal (or strobe, as appropriate) to an address (or data) IBIS-AMI receiver GetWave model using the clock_times pointer defined by the IBIS specification. A new AMI reserver parameter, Rx_Use_Clock_Input, is used to enable this functionality.

Open LPDDR5X Clock Forwarding Kit

Open the LPDDR5X Memory-Down Clock Forwarding kit in the Parallel Link Designer app using the openSignalIntegrityKit function.

openSignalIntegrityKit("LPDDR5X_CF")

Kit Overview

• Project name: LPDDR5X_CF

• Note: Widebus sheets are required for clock forwarding analysis.

Typical DDR5 Coupled Channel Simulation Setup Using Clock Forwarding

The clock times or waveform generated by DQS is passed to DQ[n:n+1] using the DQ DLL clock_times pointer.

The DQ DLL then operates on these clock times as desired (for example: triggering DFE taps, modelling DQS delay tree, or centering the DQ on the DQS waveform) and then passes out the same or modified clock_times.

Related Topics

• LPDDR5X Architectural Kit
• LPDDR5X IBIS-AMI Models with Clock Forwarding (SerDes Toolbox)