Conveyor Belt Analogy, 240 | Agilent Technologies 16760A manual

Chapter 6: Concepts

Understanding Logic Analyzer Triggering

Understanding Logic Analyzer Triggering

Setting up logic analyzer triggers can be difficult and time-consuming. You could assume that if you know how to program, you should be able to set up a logic analyzer trigger with no difficulty. However, this is not true because there are many concepts that are unique to logic analysis. The purpose of this section is to describe these key concepts and how to use them effectively.

•“The Conveyor Belt Analogy” on page 240

•“Summary of Triggering Capabilities” on page 242

•“Sequence Levels” on page 242

•“Boolean Expressions” on page 245

•“Branches” on page 246

•“Edges” on page 246

•“Ranges” on page 246

•“Flags” on page 247

•“Occurrence Counters and Global Counters” on page 247

•“Timers” on page 248

•“Storage Qualification” on page 249

•“Strategies for Setting Up Triggers” on page 251

•“Conclusions” on page 255

See Also

“Setting Up Triggers and Running Measurements” on page 69

The Conveyor Belt Analogy

The memory of a logic analyzer can be compared to a very long conveyor belt, and the samples acquired from the Device Under Test (DUT) as boxes on the conveyor belt. At one end, new boxes are

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Agilent Technologies 16760A manual Understanding Logic Analyzer Triggering, Conveyor Belt Analogy, 240

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 Eye Scan Tab 204 210211 Specifications and Characteristics 240259 Glossary Index Contents Getting Started Eye scan sampling mode, measurements will have these steps Probing and Sampling Mode Selection Steps Next . Choose the sampling mode onConnect logic analyzer to the device under test Choose the sampling mode To choose the sampling mode If you chose Timing Mode If you chose State Mode Next . Format labels for the probed signals on Either Timing Mode or State ModeIf you chose Eye Scan Mode Format labels for the probed signals To assign pods to the logic analyzer To specify threshold voltages Next Defined threshold voltage Select the Close buttonTo assign names to logic analyzer channels Timing Mode or State Mode Steps Define the trigger condition Run the measurement Next . Run the measurement on Display the captured data Next . Display the captured data onTo open Waveform or Listing displays 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 To automatically adjust sampling positions Automatically sets the sampling positionRun simultaneously Choose the labels that you wish to run eye finder on To run eye finder repetitively To view eye finder data as a bus composite To view eye finder data as a stack of channelsTo save/load eye finder data To manually adjust sampling positions Eye Finder Advanced Settings Dialog onEye finder data must be saved and loaded separately Either Timing Mode or State Mode To specify the trigger positionTo set acquisition memory depth 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 Format tab has activity indicators that show signal levels Formatting Labels for Logic Analyzer ProbesTo assign pods to the analyzer Capturing Data on 17 Channels in State Mode To set up qualified eye scan measurements onTo set pod threshold voltages To set clock threshold voltages To assign probe channels to labels Maximum of 32 channels can be assigned to a label Label offTo delete labels Signals To import label names and assignments from a netlistE5378A and E5380A probe types to be selectable Label To import label definitions from an Ascii file To assign label name Blue to channel 5 on pod A2Label Definition File Format Examples To export label definitions to an Ascii file To change the label polarityChannel 5 on pod A2, and channel 6 on pod A1 To reorder bits in a label Changing the label polarity will have the following effectsChanging the label polarity does not affect 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 Setting Up Triggers and Running Measurements Use trigger functions for basic measurementsGeneral 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 insert a reset occurrence counter action To group eventsTo use named 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 display symbols for data values To view symbolic values in a waveform displayTo view symbolic values in a listing display To cancel the display processing of captured data Select the Cancel button100 Using Symbols You can use symbol names in place of data values when101 To load object file symbols To reload object file symbols102 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 To create an Ascii symbol file General-Purpose Ascii GPA Symbol File Format on106 Create the reader.ini file on your workstation or PC StabsType ReadOnlyTicoffPageAppendTicoffPage Examples Example for Elf/Stabs Example for Coff/Stabs using Ticoff reader Example for Ticoff109 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 Cross-Triggering To cross-trigger with another instrument112 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 Service Center for assistance System help volume115 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 To set the eye scan range and resolution Scan Settings Subtab on120 To quickly set up another measurement using the scale see To run an eye scan measurementTo set advanced eye scan options 121 To set up qualified eye scan measurements Advanced Subtab on122 Requirements Signal Timing Burst Transfers Memory device versus a memory controller123 Has adjustable sampling positions on each input channel BurstAfter the rising edge of the clock Before the clock edge to after it Clock cycle of the next burst Are supported125 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 Displaying Captured Eye Scan Data To open the Eye Scan display133 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 Is zero by default Make measurements on the eye scan data on141 To make measurements on the eye scan data About the captured measurement data142 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 Loading Logic Analyzer Configurations on Saving and Loading Captured Eye Scan Data152 Sampling Tab on Format Tab on Trigger Tab on 153 154 Sampling Tab Sampling tab lets you choose between the logic analyzers155 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 State Mode State Speed158 Sampling Positions Dialog 159 Sampling Positions Tab File menu Lets you save/load eye finder data160 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 Overview Subtab This tab gives a picture of the trigger sequence189 Default Storing Subtab Event Specification ListAt start Acquisition Group events Status Subtab Save/Recall Subtab191 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 Symbols Selector Dialog Matching Symbols195 Search Pattern Offset By OptionAddress masking is done by the Align to x Byte option Symbol File Formats Align to x Byte OptionByte option allows you to mask off an address Qualifies any address from 100C through 100F General-Purpose Ascii GPA Symbol File Format 107 file198 GPA Record Format Summary Format199 Records Definitions in the file200 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 Branch expression is too complex General Guidelines212 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 Specific Guidelines 800 Mb/s State Mode Specific Guidelines 1250/1500 Mb/s State Mode216 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 No Trigger action found in the trace specification Slow or Missing Clock221 Trigger function initialization failure 222 Trigger inhibited during timing prestore Trigger Specification is too complexThen the approximate time is 32 seconds 223 Combiner resource allocation guidelines Event224 Waiting for Trigger Misaligned boundaries for addresses225 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 1500 Mb/s Sampling Mode Specifications and Characteristics E5380A Input Equivalent Circuit230 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 Understanding Logic Analyzer Triggering Conveyor Belt Analogy240 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 Agilent 16715A trigger user interface Pattern2 occurring immediately after Pattern1252 Same trigger as If/Then statements Store range until pattern occurs253 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 Understanding State Mode Sampling Positions To accurately capture data on a bus256 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 Glossary Asterisk * See edge terms, glitch, and labels263 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 By the channel width of the instrument Processor probe See emulation270 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