HP 1652B Logic Analyzer

User Information ©

Table of Contents

• Introduction
• Operation Information
  • Notation used
  • General Background
  • Power UP
  • Front Panel
  • Menu Overview
  • System Configuration Menu
  • Oscilloscope Operation
    • FORMAT/CHAN Screen
    • TRACE/TRIG Screen
    • DISPLAY Screen
  • Logic Analyzer State Operation
    • State Format Specification Menu
    • State Trace Specification Menu
    • State Listing Menu
  • Logic Analyzer Timing Operation
    • Format Specification Menu
    • Trace Specification Menu
    • Timing Waveforms Menu

Introduction

The HP 1652B Logic Analyzer is a general-purpose logic analyzer with a built-in digitizing oscilloscope. It has 80 data channels and 35 Mhz state analysis. Timing analysis is available for signals with frequencies up to 100 MHz.

This product was transferred to Agilent Technologies when HP reorganized. Agilent discontinued support for the product. Several of the original HP manuals are available in pdf form:

• Getting Started Guide (6.6 MB)
• Front-Panel Operation Reference, Vol. 1 of 2 (17.3 MB)
• Front-Panel Operation Reference, Vol. 2 of 2 (19.8 MB)

Operation Information

1. Notation. Panel controls will be indicated by <key>. Field names will be indicated by FIELD.

2. Background. This unit is a logic analyzer and a digitizing oscilloscope.
   • Logic Analyzer.
     The HP 1652B has 5 pods (labeled 1 to 5). Each pod has 16 probes (labeled 0 to 15), a clock input, and a ground input. This means that up to 80 separate logic signals can be monitored simultaneously. The HP 1652B has two separate logic analyzers that work independently (note: only one can be monitored or changed at a time). The logic analyzers have two modes: STATE and TIMING. State mode uses an external clock signal and allows the user to view "states" of the input signals and to specify trigger and storing conditions. Timing mode uses an internal clock signal (sampling at 100MHz) and allows the user to perform time analysis measurements on the input signals.

   • Oscilloscope.
     The HP 1652B is a two-channel digitizing oscilloscope. Inputs to the two channels are available from the front panel.

3. Power UP. Before powering up the system, be sure that a copy of the HP 1652B Operating System is in the disk drive. The power switch is located in the back of the unit, in the middle at the top.

4. Front Panel. A drawing of the front panel of the HP 1652B is shown below. Some of the items found on it are described below.



• Cursor: The cursor in the display area permits access to various fields in each menu. To help you locate the cursor, the system changes the field over which it is positioned to inverse video. Use the knob to move the cursor from field to field.

• Menu Keys: These are used to select the menu you wish displayed.

• Roll Keys: Used to control the direction the knob will move the cursor when listing data or displaying a waveform that needs more than one screen to completely display.

• Knob: The action caused by turning the knob depends upon the menu or submenu you are in. It can
  • move the cursor from one field to the next
  • roll the display
  • position the cursor on options within pop-up menus
  • increment or decrement numeric values



5. Menu Overview. The System Configuration menu is used to set up the HP 1652B; it is the initial menu into which the unit boots up. From this menu the user can assign pods, turn on or off a function (logic analyzer or oscilloscope), and specify what mode an analyzer is in. There are three "menus" in each operating mode:
   • format specification (labelled as FORMAT/CHAN),
   • trace specification (labelled as TRACE/TRIG), and
   • a screen to display the data (labelled as DISPLAY).

   These screens are accessed by using the "menu" keys on the keypad. The format specification menu is used to indicate inputs and specify clocking details. The trace specification menu is used to specify the events that should trigger the analyzer to begin storing data. The display screen is used to view the stored data after it has been stored. Although the sampled waveforms are visible in all three screens, the DISPLAY screen allows the user to take measurements on the waveforms.

6. System Configuration Menu.
   
   This is the screen that the unit starts with after booting up. The knob can be used to move the cursor to various boxes. For example moving to the box marked "Oscilloscope" permits you to use the <select > key to toggle the scope ON/OFF.

   The user can return to this menu at any time by moving the cursor to the "menu title" field in the upper left corner of the display, pressing <select >, then choosing SYSTEM.

   To use the logic analyzer function only, the Oscilloscope must be set to OFF. The mode of each analyzer can be assigned by pressing <select > on the name field of the appropriate analyzer (one or two).
   The logic analyzer modes are

   • TIMING,
   • STATE, and
   • OFF.

   Pod Assignment: Each pod can be independently assigned to one of the analyzers (but not both). To assign a pod, move the cursor to the appropriate pod field, and press <select >, then select the analyzer to which the pod is to be assigned to (it may also be specified as Unassigned).

7. Oscilloscope Operation. The oscilloscope operation is obtained by going to the System Configuration Menu. From this menu set the Type: fields on both Analyzers to OFF and toggle the ON/OFF field on the Oscilloscope section to ON. Then the scope channel setup is done from the FORMAT/CHAN menu, any trigger conditions can be set from the TRACE/TRIG menu, and the trace results can be viewed from the DISPLAY menu.
   • FORMAT/CHAN screen. This screen is reached from the System Configuration menu by pressing the key marked "FORMAT/CHAN" from the bank of buttons on the keypad marked "menu". Then the cursor knob is used to get to each of the parameters described below.
     • INPUT : Selects which probe will be considered the primary input for the scope. Use the <select > key to toggle between CH 1 and CH 2 according to which probe you are using.
     • V/DIV : Volts Per Division. Used to set the vertical sensitivity of the channel selected in the INPUT field. Vertical sensitivity determines the scaling of the waveform displayed (also determines maximum signal voltage without clipping). Press <select > to display the "pop-up" window, then use the knob to change the value, or simply enter the exact value using the keypad. This value may range from 150 mV/div to 100 V/div (typical value is 1.5 V/div which is the preset for TTL logic). When using the knob, press <select > to leave the "pop-up" window. When using the keypad, use the knob to toggle between V and mV and press <select > to leave the "pop-up" window. Note: changes made to this field will not be reflected until the next waveform is captured.
     • OFFSET : A DC voltage that is added to or subtracted from the input signal. This is useful for displaying the signal, which is usually small variations in a relatively large DC signal, in the center of the display area. This field may be changed using the same procedure as the "V/DIV" field. If using the keypad and a negative number is desired, enter the number and use the <CHS > key to the right of the decimal point. A typical value is 2.5 V (TTL preset value).
     • PROBE : Probe attenuation factor. This should normally be set to 10:1.
     • IMPEDANCE : Input probe impedance. Use the <select > key to toggle between 1 M-ohm and 50 ohms. This should be set to 1 M-ohm if the 10430A probes are being used.
     • PRESET : Automatically sets V/div and trigger values to properly display TTL or ECL gates. When the value USER is selected, these fields are defined by the user, otherwise they are set to an appropriate value for the logic family.
     • s/DIV : Seconds per division. Sets the horizontal sensitivity. This field can be changed using the same procedure as "V/DIV". A very important note is that the scope's "sample period" is a direct function of the "s/DIV" field.
     • DELAY : Used to view different parts of the current waveform. A delay of "0" indicates the part of the waveform where the trigger occurred, and a delay of "n" displays the portion of the waveform "n" seconds from the trigger point. Use the keypad to go to a specific time, or use the knob to "scroll" through the waveform. Changing this field does not resample the signal.
     • AUTO SCALE : This function automatically sets all the scope inputs to best display the trigger point. This isn't very useful for viewing whole waveforms. For further information see the HP 1652B manual.

   • TRACE/TRIG Screen. This screen is used to modify the trace and trigger conditions of the scope.
     • MODE : Indicates when the scope should trigger. The scope can trigger immediately (IMMEDIATE) or it will wait for a rising/falling edge (EDGE) before starting its capture. Use <select> to toggle between the two values.
     • SOURCE : Indicates which probe is to be the source for the trigger condition. Use <select> to toggle between "CH1" and "CH2".
     • RUN MODE : This field is used to select how the scope will run its trace. It can run in either SINGLE mode (indicating single shot mode, i.e. captures only once), or in REPETITIVE mode (performs the single shot function repeatedly until <stop> is pressed). <select> toggles this field.
     • LEVEL : Indicates the voltage which will cause the scope to trigger (assuming EDGE mode is used). Use <select> to change this field, and then use the knob to enter the desired value, or simply enter the exact value using the keypad.
     • AUTO-TRIG : When auto-trigger is OFF the scope will wait indefinitely for a trigger condition to occur. When it is ON the scope will wait for approximately 1 second, and if a trigger condition has not occurred, it automatically triggers.
     • ARMED BY : This field allows the scope to be armed by an external source (like a switch, etc.), a logic analyzer source (e.g., trigger the oscilloscope when an IC counter value reaches 256), or by the <run> key on the 1652B keypad.

   • DISPLAY Screen (Waveforms Menu). This is the main screen for viewing waveforms; you will spend most of your time on this screen.
     • DISPLAY : When set to AVERAGE, the scope will display the average of the last "n" waveforms; this is useful in REPETITIVE mode to get a better representation of noisy input signals. When set to ACCUMULATE, the scope draws the next waveform directly over the previous waveform(s). When set to NORMAL the scope displays only the current waveform. Use <select> and the knob to change this field.

     • CONNECT DOTS : When set to ON the scope connects the sample points so that it is easier for the user to see.

     • GRID : Use <select> to toggle the display grid on/off.

     • AUTO MEASURE : Performs automatic calculations (frequency, peak to peak voltage, period, rise time, etc.) using the wave form currently displayed on the screen. Note: To work correctly, complete waveforms must be present on the screen (use s/div to adjust).

     • MARKERS : Turns the display markers on/off. TIME mode turns the "X" and "O" markers on. These markers allow you to pinpoint values on the display. When set to TIME mode, the distance (in seconds) between the "X" and "O" marker is represented in the "X to O" field. Use <select> to change this field, then moving the knob moves both the "X" and the "O" markers together along the display (changing the "trigger to X" and "trigger to O" fields, but leaving the "X to O" field the same value, use the keypad to change the actual "X to O" value. The trigger point is represented by the darker dashed line in the middle of the display with arrows on top and bottom, this indicates the point in time where the scope triggered. The "trigger to X" and "trigger to O" points are the values (in seconds) from the trigger point to "X/O" respectfully. Use <select> to change these fields, then use the knob to move the markers along the display, or use the keypad to enter the exact value. Note that the voltage values at "X" and "O" are displayed on the left side of the display screen, on the vertical axis. The SEARCH mode allows you to specify marker conditions. To use this mode, set the MARKERS field to SEARCH, then go to the SPECIFY MARKER field in the upper right of the screen and press <select>. The TYPE field on this pop-up menu selects the type of marker condition, PERCENT (10% to 90% of peak voltage), or ABSOLUTE (an actual voltage value, e.g. 1.53 V). The "X-marker" and "O-marker" fields indicate the position of the "X" and "O" markers (e.g., if "X-position" were set to CH 1, 10%, the "X" marker would get placed on the display at the point where the waveform on CH 1 was equal to 10% of its peak value. The STOP MEASUREMENT field is used to stop the scope if/when an exception condition occurs (X<O, X>O, in range, not in range, etc.). Once these fields have been set, the STATISTICS mode under the MARKERS field is then used to obtain "X to O" values. The MARKER functions make this digital storage oscilloscope very powerful and allows for very accurate time and voltage measurements, and eliminates the error caused by "eye-balling" values on oscilloscopes.

     • Channel Fields : Located immediately to the left of the wave form display areas, usually marked CH 1 or CH 2. These fields allow you to display the waveforms in a variety of different ways. You can insert another display, delete, shut off, or modify this display. The modify and insert options allow the user to perform waveform mathematics. You can display CH1+CH2, CH1-CH2, CH2-CH1, CH1 and CH2 on same display, etc. If you delete all but one display, the remaining display will occupy the entire display area allowing a more detailed view of larger waveforms.

8. Logic Analyzer State Operation. To put one of the logic analyzers in "State" operation, select the STATE mode on the appropriate analyzer in the "System Configuration Menu"
   1. State Format Specification. To access this screen, press the <FORMAT/CHAN> key on the "menu" area of the keypad.
      • CLOCK: Indicates which clock the analyzer should use. Clocks are specified as J-N (located on pods 1-5 respectively), and the positive or negative edge can be used. There must be at least one clock specified, but more than one clock can be combined to provide some powerful and useful clocking arrangements.

      • CLOCK PERIOD: If the clock frequency of the system being analyzed is greater than 16.67 MHz (period of less than 60 ns), the <60ns value should be used, >60ns should be used otherwise since it provides better noise immunity and increases available sample storage.

      • Pod Area: Under each pod number assigned, there are two fields. The first indicates what type of logic is connected to it (TTL, ECL, or USER DEFINED). The other field indicates the clocking mode to be used on this pod. NORMAL specifies clocking will be done using the arrangement described in the CLOCK field. DEMULTIPLEXED allows clocking of two types of data occurring on the same line. MIXED CLOCKS allows the lower eight bits of a pod to be used separately from the upper eight bits.

      • Label Area: Allows a label to be defined for certain bits from one or more assigned pods (a label can also be enabled or disabled here). There are 20 labels available, and up to 32 bits can be assigned to each label. Only 11 labels are shown, but the others can be accessed by using the up/down roll key and the knob.

      • Bit Assignment Field: These fields are located under each of the assigned pods, to the right of the Label fields and are marked "15....87....0". A "*" indicates an assigned bit, and a "." indicates an unassigned bit. To change this field place the cursor on the bit field of the label to be changed and press <select>, then use the knob to move the cursor to the bit(s) to be changed (<select> toggles the bit between "*" and ".", and the <clear entry> key on the keypad sets all the bits in the selected field to ".")

      • Label and Bit assignment example: Suppose a ROM chip had 24 address lines that a user wished to monitor. Probes 0 to 15 from pod 1 could be attached to the lower 16 bits of the address lines, and bits 0 to 7 of pod 2 could be assigned to the upper 8 bits of the address lines.

        The following bit assignments could be made:

        Label	Pod 2	Pod 1
        ADDRESS	........********	****************
        LOW BYTE	................	........********
        HI BYTE	********........	................
        ODD BITS	*.*.*.*.*.*.*.*.	........*.*.*.*.
        MSBit	*...............	................

        The label "ADDRESS" would be used to refer to all 24 bits as one logical unit, even though the bits are on different pods.

      • POL Field: Specifies whether the label should be displayed as positive (+) or negative (-) polarity ( <select> toggles ). Negative polarity inverts the data of positive logic gates (e.g., voltage levels of LLHH normally displayed as %0011 is displayed as %1100).

      • SPECIFY SYMBOLS: Used to define a table of symbols for each label. If desired, the symbols are substituted in the state listing for the values to which they correspond (e.g., %110011 could be replaced by "STATE A", or all values from 0x00 to 0x0F could be replaced by "ZERO TO FIFTEEN"). Symbols are especially useful for disassembling machine code into assembly language when using the logic analyzer to monitor microprocessors.
        • Label Field -- indicates the label that this symbol table is assigned to. This can be changed by putting the cursor on the field an pressing <select> , then choose the appropriate label.
        • Base Field -- indicates the numeric base in which the values will be specified (binary, hex, octal, ASCII, decimal). Note that values cannot be specified in the "ASCII" base, the value must be entered in another base, then the base can be changed to "ASCII" if desired.
        • Symbol Name Field -- allows the user to delete, change, or insert a new symbol. The first field following this field defines the symbol as a PATTERN or a RANGE (<select> toggles). If PATTERN is selected, the field following this field defines the numerical pattern which will specify this symbol. If RANGE is selected, the following two fields define the range of values that specify this symbol.
        • Symbol View Size Field -- indicates the number of characters (1 to 16) to display when a symbol is used. For example, if a symbol name was "DATA INPUTS", the view size was set to 4, only the word "DATA" would appear when the symbol was used. This is useful when watching many labels on multiple pods when long symbol names aren't practical but are already assigned.

   2. State Trace Specification. To access this screen, press the <TRACE/TRIG> key on the "menu" area of the keypad. This menu allows the user to specify exactly what series of events should trigger the scope and cause it to start storing data.
      • Trace Mode: <select> toggles this field between SINGLE and REPETITIVE modes. SINGLE mode indicates that the analyzer will only go through the trigger sequence once, REPETITIVE mode indicates that it will repeat the sequence indefinitely.
      • Armed By: Indicates what physical device will start the trigger process, the "run" key, an external trigger switch, or another analyzer or the oscilloscope (if active).
      • Branches: Allows branching functions to be included in the sequence levels. This is an advanced feature.
      • Count: Enables a count of states between stored states, or the elapsed time between stored states. Note that using this feature cuts the sample memory in half, and cannot be used when the CLOCK PERIOD field is set to <60ns.
      • PRESTORE: <select> pulls up a "pop-up" menu with ON/OFF choices for this field. When on, the analyzer will store two "qualified" states before each state that is stored due to the sequence levels described below. The user is prompted to define the "qualified" state.
      • Label>Field: Indicates that the values directly under a particular label are associated with this label name.
      • Base>Field: Indicates the numerical base of the values.
      • Qualifier Field: There are two groups of 4 pattern recognizers, (a-d) and (e-h), and one range qualifier. This field is the large box at the bottom left of the screen with "a" through "d", or "e" through "h", or "range" displayed in it. This field is used to toggle between these three groups.

      • Pattern Fields: These are the fields directly to the right of the Qualifier field. These fields define the patterns to use for searching and storing functions (depending in the described sequence). The <DON'T CARE> key can be used to put don't care terms (represented with an "x") in this field.

        Example:

        

        In the example above, the tag "a" is used to specify the event that all 24 lines in the ROM chip, which are referenced with the label "ADDRESS", are high. Likewise, "b" specifies the event that only the lower byte is high, "c" and "d" specify any state.

      • Sequence Level Area: Used to describe the sequence the logic analyzer should perform for triggering and storing data. To change a level, put the cursor on it and press <select>. The easiest way to explain the use of this field is to give an example:

        

        Example explanation:

        

   3. State Listing Menu. To access this screen, press the <display> key in the menu area of the keypad. This screen is used to display the data that the state analyzer acquires. The default display mode is table form; to change to other modes, place the cursor on the field marked STATE LISTING, press the <select> key, and then use the knob to choose the desired mode. Descriptions of the available modes follow.
      • State Listing Mode. This is the default mode for displaying the acquired data. In this mode, the data is represented as numbers in table form. In the left column are the stored state numbers, and the column(s) to the right are the values obtained by the analyzer (after <run> is pressed). If more than five labels are used , use the Left/right arrow key on the keypad and the knob to scroll the screen to display the desired labels. Also, to view states not shown on the display, use the Up/Down arrow key on the keypad and the knob to scroll through the state numbers. The data can be displayed in different forms (hex, decimal, binary, octal, ascii, or use the symbols defined in the symbol tables for each label) by changing the BASE field under the label to modify. The labels can be rearranged on the display by pressing <select> on the Label fields. When the TIME or STATES option is selected in the COUNT field (State Trace Specifications Menu), the acquired data will be displayed with time or state tags. The MARKERS field allows the user to specify how the "X" and "O" markers will be positioned on the state listing. If the PATTERN option is specified (press <select> while cursor is on MARKERS), the patterns on which to place the markers can be specified. The find-from field specifies the number of pattern occurrences the analyzer should search for. This search begins after the reference point, which is specified in the next field. If more than one label is used, patterns can be specified for each label and the analyzer performs an "AND" function to place the markers. When the TIME or STATES option is selected in the COUNT field (State Trace Specifications Menu), other advanced marker functions are available.

      • State Waveforms. Specifies that the state data will be displayed in the form of waveforms identified by label name and bit number. Up to 24 waveforms can be displayed simultaneously. To select a waveform to display, move the cursor to the fields in the left column next to the display area and press <select>, then choose the label and bit numbers to display. From here, a waveform can be inserted, deleted, modified, or toggled on or off. The MARKERS are similar to the marker operations in the State Listing mode, except the "X" and "O" markers are placed over the waveforms instead of on the numbers.

      • State Chart. Provides the ability to build X-Y plots of label activity using state data. For example, you could plot "Label 1" VS "Label 2".

      • State Compare. Provides the ability to do a bit by bit comparison between the current acquired state data listing and a compare data image (stored previously). This is a very useful tool for finding hard to detect bugs or bugs that do not occur at predictable times.

9. Logic Analyzer Timing Operation. To put one of the logic analyzers in "Timing" operation, select the TIMING mode on the appropriate analyzer in the "System Configuration Menu". In the timing mode, the analyzer acquires data asynchronously using an internal sample clock. The sample rate is always set to 10 ns. The timing mode is similar to the digital storage oscilloscope, except that it only stores and displays two voltage levels (above and below the threshold voltage) for each of the 80 inputs.
   1. Timing Format Specification Menu. To get to this screen, press the <FORMAT/CHAN > key in the "menu" portion of the keypad. This menu is exactly the same as the "State Format Specification Menu" except that the CLOCK is not used in the timing mode (since the sample clock is internal). Symbols and labels are conserved when switching a machine between the two modes (TIMING and STATE)

   2. Timing Trace Specification Menu. To get to this screen, press the <TRACE/TRIG> key in the "menu" portion of the keypad. This menu is used to define the parameters used to trigger the analyzer, and its behavior after triggering.
      • Trace Mode Field -- Use <select> to toggle between SINGLE and REPETITIVE modes. In SINGLE mode, the analyzer only triggers one time. In REPETITIVE mode, the analyzer triggers repeatedly until <stop> is pressed. These two modes operate the same as the single/repetitive modes of the DSO.
      • Armed By Field -- Sets analyzer up to arm using the <run > key (RUN), an external input (BNC Input), or by the DSO and the other analyzer if they are enabled.
      • Acquisition Mode Field -- <select> toggles between GLITCH and TRANSITIONAL. In TRANSITIONAL mode, the analyzer samples at a rate of 100MHz, but only stores data in memory when transitions occur (i.e. when the signal goes from 0(1) to 1(0), the event is recorded along with a time stamp indicating when the transition occurred, this allows the analyzer to reconstruct the waveforms after data acquisition has completed). This provides maximum timing resolution when long time windows are monitored. GLITCH mode is used to catch signals glitches in the inputs. In this mode, the analyzer can detect glitches as small as 5ns. Glitches are represented by dashed lines in the displayed waveforms. Note that when using this mode, sample memory is cut in half.
      • Find Pattern Field -- Specifies the condition which triggers the timing analyzer. If more than one label is used an "AND" operation is performed to trigger on the specified patterns. "Don't Care" terms (represented with an "X") can be specified in this field using the <DON'T CARE> key on the keypad. The fields following this one are used to specify the time the pattern must be present, and what to do after the event is found. The fields are self explanatory, and are all changed using the <select> key.

   3. Timing Waveforms Menu. To get to this screen, press the <DISPLAY> key in the "menu" portion of the keypad. This is where the waveforms are actually displayed. Note that no data is displayed here until a <run> has been done.
      • ACCUMULATE Field -- When ON, the analyzer displays data from a current acquisition on top of the previously acquired data. Use <select> to toggle between ON/OFF.
      • Time/Div Field -- Used to change the horizontal scale. This works the same as the S/DIV field in the DSO. Note that changing this field does not affect the sample period, which is always set to 10ns
      • Label/Bit Fields -- These fields are located to the left of the waveform display area. Waveforms can be inserted, deleted, or modified using the Label field. The bit field defines which bit of that label is to be displayed in this position.
      • Markers Field -- The markers in timing mode are similar to those in the DSO, with the added feature of being able to specify a pattern (if PATTERN mode is selected) to place the "X" and "O" markers.