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Test setup – Xilinx Virtex-5 FPGA ML561 User Manual

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Virtex-5 FPGA ML561 User Guide

UG199 (v1.2.1) June 15, 2009

Chapter 7: ML561 Hardware-Simulation Correlation

R

illustrated here for these signals can be easily adopted to perform SI analysis for any other
memory interface signal on the ML561 board.

This chapter presents the SI results for the following six data bit signals:

DDR2 component DQ bit (DDR2_DQ_BY2_B3) for write operations

DDR2 component DQ bit (DDR2_DQ_BY2_B3) for read operations

DDR2 DIMM DQ bit (DDR2_DIMM_DQ_BY2_B3) for write operations

DDR2 DIMM DQ bit (DDR2_DIMM_DQ_BY2_B3) for read operations

QDRII D bit (QDR2_D_BY0_B5) for write operations

QDRII Q bit (QDR2_Q_BY0_B5) for read operations

Test Setup

Hardware measurements were performed for the six specific signal nets, and then signal
integrity (SI) simulations were performed for correlation and extrapolation. The test setup
consisted of the following hardware equipment, simulation software tools, the stimulus
test pattern, and test criteria for determining the quality of signals. The test bench is
designed so that the test pattern is applied only to the signal under test, and all other data
bits to the same memory interface are kept in a quiet Low state. This setup ensures that the
hardware measurement is not altered due to any simultaneous switching output (SSO)
effect.

Hardware measurement equipment

Agilent DSO80604B 6 GHz oscilloscope

Agilent 1131A 3.5 GHz Infiniimax probe amplifier

Agilent E2675A (Differential browser) or E2677A (Differential solder-in probe) or
N5425A (ZIF probe)

Virtex-5 FPGA ML561

, Rev B2 board: S/N 103

SRS Model CG635 Synthesized Clock Generator for low jitter clock source

Simulation software

Mentor Graphics HyperLynx EXT, Version 7.5 with LineSim and BoardSim
features

Xilinx Virtex-5 FPGA IBIS package file: ff1136_5vlx50t.pkg, Rev 1.0 dated
June 12, 2006

ML561, Rev B layout file: ML561_B_041706.hyp

Micron DDR2-667 IBIS model for output and ODT input

Micron PC2-5300 RDIMM IBIS model

Molex DDR2 DIMM socket specification (P/N 087705-1041)

Samsung QDRII HSTL 1.8V IBIS model

IBISWriter

Utility of ISE software suite to create customized IBIS model of the

FPGA1 (U7) and FPGA3 (U34) devices on the ML561 board: Model files
ml561_fpga1_u7.ibs

and ml561_fpga3_u34.ibs. (See

“How to Generate a

User-Specific FPGA IBIS Model,” page 93

for steps on how to create a customized

IBIS model of Virtex-5 FPGA for your design.)

Stimulus

Pseudo Random Bit Stream (PRBS) is accepted as the most effective test pattern to
measure the quality of data signals because, unlike the periodic signals like clock and