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Chapter 6: Concepts

Understanding Eye Scan Measurements

The result is a map of transitions detected in small windows of time and voltage over a range of time and voltage. Oscilloscope-like eye diagrams are used to display the measurement data. The number of transitions in each window is indicated by brightness or color.

When setting up eye scan measurements, you can define the time and voltage ranges, as well as the size (in other words, resolution) of the time and voltage windows. There are coarse, medium, and fine settings, and you can make adjustments to these settings.

Coarse settings result in faster measurements because fewer samples are collected, but the eye diagram resolution is lower (see the picture above).

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Contents

Agilent Technologies 16760A Logic Analyzer Agilent Technologies. All rights reserved Captures input signals as low as 200 mV p-p Sampling Mode onAgilent Technologies 16760A Logic Analyzer Probing Reference on Concepts on See Also Glossary see Contents Choosing the Sampling Mode Using Symbols 101 110112 114 Displaying Captured Eye Scan Data 152155 Format Tab 174 211 Eye Scan Tab 204210 259 Specifications and Characteristics240 Glossary Index Contents Getting Started Eye scan sampling mode, measurements will have these steps Connect logic analyzer to the device under test Probing and Sampling Mode Selection StepsNext . Choose the sampling mode on Choose the sampling mode To choose the sampling mode If you chose Timing Mode If you chose State Mode If you chose Eye Scan Mode Next . Format labels for the probed signals onEither Timing Mode or State Mode Format labels for the probed signals To assign pods to the logic analyzer To specify threshold voltages To assign names to logic analyzer channels NextDefined threshold voltage Select the Close button Timing Mode or State Mode Steps Define the trigger condition Run the measurement Next . Run the measurement on To open Waveform or Listing displays Display the captured dataNext . Display the captured data on Next For More Information... on To add display tools via the Workspace window Eye Scan Mode Steps Select channels for the eye scan measurement Set the eye scan range and resolution Next . Set the eye scan range and resolution on Run the eye scan measurement Next . Run the eye scan measurement on Display the captured eye scan data Next . Display the captured eye scan data on Eye Scan display window, use the following subtabs For More Information For More Information Probing and Selecting the Sampling Mode Probing and Selecting the Sampling Mode Using the E5378A Single-Ended Probe Probing the Device Under Test Single-ended signal NumberNumbers Either Using the E5379A Differential Probe Or single-ended signals Independent threshold adjustmentNegative data inputs Reference voltage Using the E5380A Mictor-Compatible Probe Or AMP Using the E5382A Single-ended Flying Lead Probe Set Using an Analysis Probe Additional Accessories Probing the Device Under Test Choosing the Sampling Mode Selecting the Timing Mode Asynchronous Sampling To select the timing mode To select the conventional/transitional configuration To specify the sample period Sample rate is the inverse of the sample period Selecting the State Mode Synchronous Sampling State Mode Sampling PositionTo automatically adjust sampling positions on To manually adjust sampling positions on To select the state mode To select the state speed configuration To set up the sampling clock For the clock input signal that will be used Run simultaneously To automatically adjust sampling positionsAutomatically sets the sampling position Choose the labels that you wish to run eye finder on To run eye finder repetitively To save/load eye finder data To view eye finder data as a bus compositeTo view eye finder data as a stack of channels Eye finder data must be saved and loaded separately To manually adjust sampling positionsEye Finder Advanced Settings Dialog on To set acquisition memory depth Either Timing Mode or State ModeTo specify the trigger position To name an analyzer To turn an analyzer off or onYou can give more descriptive names to a logic analyzer You can also name analyzers in the Pod Assignment Dialog on Selecting the Eye Scan Mode To select the eye scan modeTo select the eye scan mode speed configuration High-speed or high-bandwidth oscilloscope To set up the eye scan mode reference clock To assign pods to the analyzer Format tab has activity indicators that show signal levelsFormatting Labels for Logic Analyzer Probes To set pod threshold voltages Capturing Data on 17 Channels in State ModeTo set up qualified eye scan measurements on To set clock threshold voltages To assign probe channels to labels To delete labels Maximum of 32 channels can be assigned to a labelLabel off Signals To import label names and assignments from a netlistE5378A and E5380A probe types to be selectable Label Label Definition File Format Examples To import label definitions from an Ascii fileTo assign label name Blue to channel 5 on pod A2 Channel 5 on pod A2, and channel 6 on pod A1 To export label definitions to an Ascii fileTo change the label polarity Changing the label polarity does not affect To reorder bits in a labelChanging the label polarity will have the following effects To turn labels off or on To turn a label offTo turn a label on To display a label that was off Using the Logic Analyzer in Timing or State Mode Using the Logic Analyzer in Timing or State Mode General Setting Up Triggers and Running MeasurementsUse trigger functions for basic measurements Using Trigger Functions To select a trigger function To specify a label pattern event Timing only To enter symbolic label values on Symbols Selector Dialog on To specify a label edge event To expand a trigger function To compress a trigger function To load/unload trigger function libraries To copy trigger function libraries between systems Using Other Trigger Features To count time, states, or turn counting off To specify default storing To assign pods to the analyzer onReduced by half in order to store the required time tags If you chose Custom To clear default storing changes Default storing is initially on or off Trigger tabs Default Storing subtab, select the At startTo insert a store action state mode on Acquisition option button and choose either On or Off To insert/replace/delete sequence levels To clear the trigger sequence onTo insert sequence levels To replace sequence levels To cut/copy-and-paste sequence levels Setting Up Triggers and Running Measurements Example system14 Slot C Analyzer C has triggered To restore default trigger settings To view a picture of the trigger sequenceTo clear the trigger sequence Trigger tab, select the Overview subtab To specify a duration or occurrence count for events To specify a time duration for events timing only To insert a store action state mode To insert timer actions/eventsTo insert a timer action Available To insert a timer event To insert counter actions/eventsTo insert a counter action To insert a counter event To insert flag actions/events To drive the Port Out signal with a flag To insert a flag event To use named events To insert a reset occurrence counter actionTo group events Saving/Recalling Trigger Setups To save a trigger setupTo give an event list a name To insert a named event To recall a trigger setup Running MeasurementsTo clear the trigger save/recall list To start/stop measurements If nothing happens when you start a measurement To stop a measurementSelect the Stop or Stop All button Waiting for Trigger on To view the trigger status Displaying Captured Data To open Waveform or Listing displays Help volume To use other display toolsWindows Search for particular data values captured on labels Displaying Captured Data Analyzer help volume Intermittent Data Errors Unwanted TriggersIf the captured data doesnt look correct Into parallel words which are easier to view and analyze If there are filtered data holes in display memory This situation will occur in these cases To view symbolic values in a listing display To display symbols for data valuesTo view symbolic values in a waveform display 100 To cancel the display processing of captured dataSelect the Cancel button 101 Using SymbolsYou can use symbol names in place of data values when 102 To load object file symbolsTo reload object file symbols To adjust symbol values for relocated code Object file symbols are reloaded To create user-defined symbols Whose symbols you wish to relocateTo replace user-defined symbols 104 To enter symbolic label values When entering label values in the trigger sequenceTo delete user-defined symbols To load user-defined symbols 106 To create an Ascii symbol fileGeneral-Purpose Ascii GPA Symbol File Format on Create the reader.ini file on your workstation or PC StabsType ReadOnlyTicoffPageAppendTicoffPage Examples Example for Elf/Stabs 109 Example for Coff/Stabs using Ticoff readerExample for Ticoff Printing/Exporting Captured Data You can print captured data from display tool windows Select the file name and automatic file sequencing options Select the Read File buttonIcon to view the imported data 111 112 Cross-TriggeringTo cross-trigger with another instrument When the logic analyzer drives the arm signal 113 Solving Logic Analysis Problems To test the logic analyzer hardwareTo test the logic analyzer hardware on 114 115 Service Center for assistanceSystem help volume Saving and Loading Logic Analyzer Configurations To save logic analyzer configurationsTo load logic analyzer configurations 116 Using the Logic Analyzer in Eye Scan Mode 117 118 Setting Up and Running Eye Scan Measurements Eye Scan tab lets you set up and run Eye Scan measurementsTo select channels for the eye scan 119 120 To set the eye scan range and resolutionScan Settings Subtab on To quickly set up another measurement using the scale see To run an eye scan measurementTo set advanced eye scan options 121 122 To set up qualified eye scan measurementsAdvanced Subtab on 123 Requirements Signal Timing Burst TransfersMemory device versus a memory controller Has adjustable sampling positions on each input channel BurstAfter the rising edge of the clock Before the clock edge to after it 125 Clock cycle of the next burstAre supported 126 Be sure that the thresholds are set correctly 127 For correct state mode acquisitions Not already expandedStart your target system and select Run Eye Finder Display Now, set up eye scan mode 129 Select the Eye Scan tab Select the Qualifier subtab 130 Select the Qualify eye scan sampling using... button 131 To comment on the eye scan settings 133 Displaying Captured Eye Scan DataTo open the Eye Scan display To select the channels displayed ToolWithin the data captured on the bus 134 To scale the Eye Scan display Scale tab, you canTo use the scaling options Eye Scan display window, select the Scale tab To quickly set up another measurement using the scale To set Eye Scan display optionsTo clear the captured eye scan data To open the Eye Scan display on 137 138 139 To change the Eye Scan color scale 140 141 Is zero by defaultMake measurements on the eye scan data on 142 To make measurements on the eye scan dataAbout the captured measurement data 143 144 145 146 147 148 To display information about the eye scan data Scroll bars to navigate through the informationEye Scan display window, select the Info tab 149 Info tab, you can 150 To comment on the eye scan data 151 152 Loading Logic Analyzer Configurations onSaving and Loading Captured Eye Scan Data Sampling Tab on Format Tab on Trigger Tab on 153 154 155 Sampling TabSampling tab lets you choose between the logic analyzers Timing Mode Conventional TransitionalAcquisition 156 How Samples are Stored in Transitional Timing Will be storedPeriod and other times more than two sample periods apart Samples with transitions 158 State ModeState Speed Sampling Positions Dialog 159 160 Sampling Positions TabFile menu Lets you save/load eye finder data Label buttons Display AreaSampling Position 161 How the Selected Position Behaves How the Suggested Position BehavesXX% complete Cannot run the Eye Finder at this time Cannot run the Logic Analyzer at this time Characterizer cannot be loadedComplete Date 163 Select one or more labels in the Eye Finder Setup tab Timeout N K clocks in 5 sec This channel appears to be completely quietTwo common possibilities exist 165 Run Eye Finder to characterize this channel See individual channels for messagesStable region extends beyond the limits of the display 166 Numerical value for the item XXX could not be read Disk is probably full Failed to open file for reading/writing Name File Name already exists. Overwrite?Invalid true/false flag Unsupported revision level AA.BB Eye Finder Setup Tab 169 Eye Finder Advanced Settings Dialog 170 File Info Tab 171 Eye Scan Mode ReloadSave Save As Selecting the Eye Scan Mode on 173 Expander cards which cannot be used in the clock setup Format TabData Specify the logic analyzer pod and clock threshold voltages Pod Assignment Dialog NameType Pods Trigger Tab 176 Trigger Functions Subtab 177 General Timing Trigger Functions 178 179 General State Trigger Functions 180 Find pattern1 eventually followed by pattern2 181 182 Advanced Trigger Functions 183 184 Turbo State Trigger Functions State Trigger FunctionsAdvanced pattern1 or pattern2 Searched for 186 Half Channel State Trigger Functions 187 Settings Subtab CountIntermodule Control 188 189 Overview SubtabThis tab gives a picture of the trigger sequence Default Storing Subtab Event Specification ListAt start Acquisition Group events 191 Status SubtabSave/Recall Subtab Creating trigger function libraries 192 Symbols Tab Two kinds of symbols are availableThat you use to set up resource terms Multiple files Object file versions See Also 194 195 Symbols Selector DialogMatching Symbols Address masking is done by the Align to x Byte option Search PatternOffset By Option Symbol File Formats Align to x Byte OptionByte option allows you to mask off an address Qualifies any address from 100C through 100F 198 General-Purpose Ascii GPA Symbol File Format107 file 199 GPA Record Format SummaryFormat 200 RecordsDefinitions in the file Symbol representing the name of the section Symbol representing the function nameFirst address of the section, in hexadecimal Last address of the section, in hexadecimal You can specify symbols for variables using Name of a fileNumber of a line in the file, in decimal 202 Comments 203 Eye Scan Tab Labels SubtabExpand Collapse Shows labels only Select All Selects all channels Scan Settings Subtab Run ModeScan Range Time Advanced Subtab 206 Short MediumLong Custom Qualifier Subtab QualificationClock Edge to Sample Names for Comments Subtab 209 Calibration Tab Calibration InstructionsCalibration Status Calibration Messages Error Messages 211 212 Branch expression is too complexGeneral Guidelines Specific Guidelines 200 Mb/s State and all Timing Modes 213 If the following sequence does not compile This one maySpecific Guidelines 400 Mb/s State Modes 214 215 216 Specific Guidelines 800 Mb/s State ModeSpecific Guidelines 1250/1500 Mb/s State Mode 217 Goto action specifies an undefined level Hardware Initialization FailedPossible Causes Last sequence level calls goto next Maximum of 32 Channels Per Label Must assign another pod pair to specify actions for flagsNo more Edge/Glitch resources available for this pod pair Timing sampling mode, flags are are always available Possible Solutions No more Pattern resources available for this pod pairPhrase some of the edges as patterns 220 221 No Trigger action found in the trace specificationSlow or Missing Clock Trigger function initialization failure 222 Trigger inhibited during timing prestore Trigger Specification is too complexThen the approximate time is 32 seconds 223 224 Combiner resource allocation guidelinesEvent 225 Waiting for TriggerMisaligned boundaries for addresses To save a trigger setup on 226 Specifications and Characteristics Operating temperature 0 to 45 degrees CProbes 227 E5378A Single-Ended Probe Specifications Characteristics E5379A Differential Probe Specifications CharacteristicsAll specifications are marked by * asterisk E5378A Input Equivalent Circuit E5379A Input Equivalent Circuit 229 230 1500 Mb/s Sampling Mode Specifications and CharacteristicsE5380A Input Equivalent Circuit Characteristics 231 232 400 Mb/s Sampling Mode Specifications Characteristics 233 200 Mb/s Sampling Mode Specifications Characteristics 234 Conventional Timing Mode Specifications and Characteristics Transitional Timing Mode Specifications and CharacteristicsAll specifications are marked by * asterisk 235 What is a Specification? 236 What is a Characteristic? What is a Function Test?Referred to as an operational accuracy calibration 237 238 Concepts 239 240 Understanding Logic Analyzer TriggeringConveyor Belt Analogy Conveyor belt analogy 241 Summary of Triggering Capabilities Sequence LevelsNext Summary of Triggering Capabilities on Next Sequence Levels on 243 244 Addr Data Boolean Expressions Branches EdgesRanges Next Ranges on Flags Occurrence Counters and Global CountersNext Flags on Trigger Sequence for Module Timers Next Timers onAn example trigger sequence to set up this measurement is An edge followed by an edge with a time limit Default Storage Storage QualificationNext Storage Qualification on Needed Sequence Level Storage 250 Strategies for Setting Up Triggers Next Strategies for Setting Up Triggers onTrigger Functions 251 252 Agilent 16715A trigger user interfacePattern2 occurring immediately after Pattern1 253 Same trigger as If/Then statementsStore range until pattern occurs Setting Up Complex Triggers Next Setting Up Complex Triggers onDocument Your Trigger Sequences Next Document Your Trigger Sequences on Conclusions Different parts of the trigger to describe how they workNext Conclusions on Inline documentation on an Agilent logic analyzer 256 Understanding State Mode Sampling PositionsTo accurately capture data on a bus 257 Window 258 Understanding Eye Scan Measurements 259 260 261 Voltage resolution that can be set is 1 mV Using the Logic Analyzer in Eye Scan Mode onAre multiple logic analyzer cards in a module in this case Measurements run simultaneously in parallel 263 GlossaryAsterisk * See edge terms, glitch, and labels Divided into 1K 64-state records 264 Debug mode See monitor 265 Ethernet address See link-level 266 267 268 Module/probe interconnect cable 269 270 By the channel width of the instrumentProcessor probe See emulation Measurements 271 272 273 274 Index 275 276 251 277 247 278 122 279 180 Label values, symbolic, 105 labels, 22 280 281 Positive logic 282 242 283 107 284 Wait for other machine to trigger Publication Number 5988-9044EN January 1

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