Agilent Technologies user manual Using Eye Finder with the FS2331 DDR Probe

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Using Eye Finder with the FS2331 DDR Probe

The explanation of the procedure for calibrating the probe for optimal read and write state acquisition provides a description of some useful ways you can interpret Eye Finder results. Eye Finder can be very useful in helping characterize DDR busses. You should keep the following in mind as you interpret Eye Finder results:

1.The results displayed by Eye Finder are not quantitative. They should be used as a way to identify signals that deserve closer examination with other calibrated parametric tools (such as an oscilloscope) or to find the optimal sampling time for state analysis. They should not be used as a definitive measurement of DDR signal timing.

2.The absolute accuracy of the position of the data valid window is not specified or guaranteed. Relative positions are more accurate, but skews will exist in the FS2331/analyzer system that are not calibrated out of the Eye Finder measurement and thus will show up in the results display. These skews could total several hundred picoseconds.

3.The width of data valid windows shown in the Eye Finder results display will be less than what you would measure with an oscilloscope. The difference is about one nanosecond. This is due to additional signal jitter within the analyzer as well as an amount subtracted by the Eye Finder software to provide additional timing margin. The data valid window displayed may be as small as 100-200ps yet the analyzer may still properly sample data. Measurement of the actual window with a oscilloscope may show an eye of 1.25ns or more.

4.Eye Finder speed is a direct function of the density of analysis clocks in the stimulus used while Eye Finder runs. With frequent clocks Eye Finder will usually complete in less than 15 seconds. If Eye Finder is taking longer than two minutes to complete you can do one or more of the following to help it run faster:

∙Turn off the external CPU cache memory

∙Select the "short" option in the "Eye Finder->Advanced..." dialog

∙Use a different stimulus. Video files played in Windows Media player have performed well.

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Contents Revision DDR Sdram Analysis Probe FS2331How to reach us Product Warranty Signal Connections For Sales and Marketing Support For Technical SupportExclusive Remedies Product WarrantyLimitation of warranty Introduction Probe Cable, Connector NumberingDefinitions Logic Analyzer ModulesFS2331 100 pin Connector to Pod Diagram Probe Components Probe Feature SummaryFS2331 Probe Description Probe Design DDR CommandsState Clock Generation DDR DataPage Pod Clock Domain Clock Rate Probe Pod AssignmentOn closed Switch # Default factory Function PositionProbe Switch Settings Connecting Power to the FS2331 Probe Logic Analyzer Signal Threshold Voltage SettingsConnecting the Probe to the Logic Analyzer Card Requirements for PC2700 Systems Recommended Logic Analyzer Card Requirements16753/4/5/6 Setting up the 169xx Analyzer Setting up the 167xx AnalyzerSoftware Requirements System Software 169xx LicensingTiming Analysis All DDR speeds and supported analyzer cards Card Configurations for State Analysis Probing multiple DDR busses Interleaved memory If User is dedicating a Connecting to your Target System Chip Select§ Isolate the Dedicated DIMM’s pin Chip Select Jumper locations§ Sleeve the Pin Unused Pods § Wire from the adjacent Dimm slot to the isolated pinOffline Analysis Filtering Timing Analysis Operation Loading the Inverse Assembler and Decoding DDR CommandsState Analysis Operation Taking a Trace, Triggering, and Seeing Measurement ResultsInverse Assembler and Decoding DDR Commands Tracing the Serial Presence Detect Signals Using Eye Finder with the FS2331 DDR Probe Using EyeScan with the FS2331 Probe Dimm Signal Loading Option Using the FS2331 DDR Probe with an Interposer FS1024/25FS2331 Calibration Page Set Command sample position Page Page Write Burst Data Valid Position Page Page Page Read Burst Data Valid Position Page Page Page Set the final analyzer sample position Adjust the delay line value to maximize R/W overlapPage Standards supported General InformationSamtec Signal Connections J1 DataSA0 CB4 J2 Data and CommandSpare J3 Command and Data Buffcmdclk DM5DQS14 J4 DataDQS7
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