Agilent 16720A Help Volume

Help Volume

Instrument: Agilent Technologies 16720A 300 M Vectors/s Pattern Generator

Using the Agilent Technologies 16720A Pattern Generator

The Agilent 16720A Pattern Generator is used by digital design teams to emulate digital signals in circuits under development. The pattern generator can take the place of missing devices, or can act as a stimulus to functionally test prototypes.

Getting Started • “Overview of the Agilent Technologies 16720A Pattern Generator” on

page 10

• “A Beginner's Exercise” on page 17

Creating the Program • “Building an Initialization Sequence” on page 21

• “Building a Main Sequence” on page 23

• “Building a User Macro” on page 25

• “Importing Agilent 16522A ASCII Files” on page 28

• “Importing Agilent 16720A PattGen Binary Files” on page 39

• “Importing System Data Files” on page 58

• “Loading and Saving Pattern Generator Configurations” on page 61

See Also “Selecting the Correct Probe Pod” on page 62

“Connecting the Probe Pods” on page 71

“Editing Sequences” on page 73

“Working with Instruction Types” on page 78

“Working with Labels and Pods” on page 85

“Working with Macro Parameters” on page 98

“Working with Automatic Pattern Fills” on page 101

Using the Agilent Technologies 16720A Pattern Generator

“Printing the Pattern Generator Window” on page 108

“Printing Vector Sequences to a File” on page 109

“Viewing a Compiled Sequence” on page 116

Using the Intermodule Window (see the Agilent Technologies 16700A/BSeries Logic Analysis System help volume)

“Key Characteristics” on page 111

Main System Help (see the Agilent Technologies 16700A/B-Series Logic Analysis System help volume)

Glossary of Terms (see page 117)

Using the Agilent Technologies 16720A Pattern Generator

1 Using the Agilent Technologies 16720A Pattern Generator

Overview of the Agilent Technologies 16720A Pattern Generator 10

Mapping Probe Pods to the Interface 11 Vector Output Mode 12 Clock Source 13 Building a Sequence of Test Vectors 15 Running the Pattern Generator 16

A Beginner’s Exercise 17

Configure Format 17 Configure Sequence 18 Set up the Workspace 19 View the Results 19

Building an Initialization Sequence 21

Building a Main Sequence 23

Building a User Macro 25

Importing Agilent 16522A ASCII Files 28

Creating an ASCII File 30 ASCII Disk File Identifier 32 ASCII File Commands 32

Importing Agilent 16720A PattGen Binary Files 39

Creating a PattGen Binary File 40 Binary File Commands 42

Contents

Importing System Data Files 58

Data Sets 59 Data Set Labels 59 Data Set Range 60

Loading and Saving Pattern Generator Configurations 61

Selecting the Correct Probe Pod 62

Data Pod Descriptions 63 Clock Pod Descriptions 67

Connecting the Probe Pods 71

Editing Sequences 73

Cutting, Copying, Pasting, and Deleting Sequence Lines 73 Deleting Sequence Lines 74 Inserting Blank Sequence Lines 75 Go to a Line Number 76 Positioning the Sequence 76 Using Ditto " values 77

Working with Instruction Types 78

The Break Instruction 79 The Signal IMB Instruction 79 The Wait IMB Event Instruction 80 The Wait External Event Instruction 80 The User Macro Instruction 81 The Repeat Loop Instruction 82

Contents

Working with Labels and Pods 85

Creating and Inserting New Labels 86 Deleting Labels 87 Inserting Pre-assigned Labels 88 Renaming Existing Labels 88 Reordering a Label’s Pod Bits 89 Turning Labels On/Off 89 Clearing Format Labels 90 Searching for Labels 90 Swap Pods 90 Clear Pods 91 Assigning Bits to a Label 91 Label Polarity 92 Finding a label 92 Replace Labels 93 Appending Labels 94 Insert All Labels 95 Delete All Labels 95 Setting the Label Font Size 95 Adjusting Column Width 96 Setting Column Color 96 Setting the Numeric Base 97 Rearranging the Label Order 97

Working with Macro Parameters 98

Turning Parameters On 98 Inserting Parameters into a Macro 99 Assigning Parameter Values 99 Removing Parameters from a Macro 100

Working with Automatic Pattern Fills 101

Generating a Fixed Pattern Fill 101 Generating a Count Pattern Fill 102 Generating a Rotate Pattern Fill 103 Generating a Toggle Pattern Fill 105 Generating a Random Pattern Fill 106

Contents

Printing the Pattern Generator Window 108

Printing Vector Sequences to a File 109

Key Characteristics 111

Automatic Cursor Wrap 113

Recalling Macros 114

Copying Macros 115

Viewing a Compiled Sequence 116

Glossary

Index

Using the Agilent Technologies 16720A Pattern Generator

Chapter 1: Using the Agilent Technologies 16720A Pattern Generator

Overview of the Agilent Technologies 16720A Pattern Generator

Description of the Agilent 16720A Pattern Generator

The Agilent 16720A Pattern Generator is a tool that generates digital signals. It is used in applications that require an external source to simulate digital circuitry or generate digital signals for functionally testing prototype hardware.

Combined with the analog and digital measurement capabilities of the logic analysis system, you have a tightly integrated solution to your digital stimulus and response measurement needs.

A Conceptual Measurement Example

The exact output pattern, clock type and speed, and number of required signals depends on your specific application. How you configure the pattern generator and what kind of signal generation sequence you create will vary. However, from a procedural standpoint, the steps are the same each time to set up, create a sequence, and run the pattern generator.

1. Select the probing (see page 62) that is compatible with your target circuit.

2. Set the Vector Output mode (see page 12) and the Clock Source (see page 13) parameters.

3. Connect the probes (see page 71) to your circuit and map the probe channels (see page 11) into the interface of the pattern generator.

4. Build a sequence of test vectors (see page 15) to generate the desired output signals.

5. Run (see page 16) the pattern generator and measure the active target circuit or prototype for the desired results.

Re-using Pattern Generator Programs

After you set up a pattern generator configuration, you may want to store it away so you can use it again. Perhaps you want to create a set

Chapter 1: Using the Agilent Technologies 16720A Pattern Generator

Overview of the Agilent Technologies 16720A Pattern Generator

of test routines or circuit simulators. There are three ways to handle re-usable configurations.

• You can reload previously saved (see page 61) pattern generator configurations.

• You can import an Agilent 16522A ASCII file (see page 28) (can only be used for vector sets <= 1048576 vectors)

• You can import a Agilent 16720A PattGen Binary file (see page 39) (must be used for vector sets >1048576 vectors)

See Also “A Beginner's Exercise” on page 17

“Key Characteristics” on page 111

Mapping Probe Pods to the Interface

While the probes make the physical connection to your target circuit, a software connection is also made within the interface which routes generated signals to the proper probe output lines. This software connection is done within the Format tab and is called mapping.

The mapping process consists of logically grouping output signals that have a similar purpose to a label (see page 85) with a unique name. To add to or delete signals from a group, you simply turn On/Off the bits (see page 91) beside the label.

Example

This example shows eight channels (or bits) on probe pod 1 mapped to two labels in the interface. Bits 0-3 are assigned to label Bus_A, and bits 4-7 are assigned to label Bus_B. When a bit is assigned, an asterisk "*" appears in the bit assignment field, verifying the software connection.

Chapter 1: Using the Agilent Technologies 16720A Pattern Generator

Overview of the Agilent Technologies 16720A Pattern Generator

NOTE: After you set up your first measurement, use the ribbon cable ID clips to mark

the data cable numbers for future reference.

Vector Output Mode

The Vector Output Mode determines the channel width, available pods, and the frequency range for both the internal and external clock. The choice you make may be determined by trade-offs between clock speed and channel width.

Because the output mode affects clock frequency ranges, available pods, and channel width, keep your mode selection in mind when designing the circuit’s hardware interface and when mapping probe connections between the test circuit and the labels of the pattern generator.

This table shows the difference between the Full-Channel 180 MBits/s mode and the Half-Channel 300 MBits/s mode.

Chapter 1: Using the Agilent Technologies 16720A Pattern Generator

Overview of the Agilent Technologies 16720A Pattern Generator

Clock Source

The Clock Source field toggles between internal and external. The internal clock source is supplied by the pattern generator and controls the frequency used to output the vectors to the system under test. The external clock is provided by the user or the system under test, and is input to the pattern generator through the CLK IN probe of a clock pod.

An advantage of using an external clock is that you synchronize the vector output of the pattern generator to the system under test. No matter which clock source is used, vectors are always output on the rising edge of the clock.

Internal Clock Source

Use an internal clock source when you want to have control over the frequency of the output vectors and it is not important for the output vectors to be synchronized to the system under test.

You select clock frequencies in steps of 1. If you use the keypad to select a value between the step intervals, the value is rounded to the nearest interval.

Chapter 1: Using the Agilent Technologies 16720A Pattern Generator

Overview of the Agilent Technologies 16720A Pattern Generator

NOTE: If you use the keypad to change the the clock frequency value, you must press

the Enter key to register the new value. You are not required to type "Hz", you may use only a metric prefix or you may enter a floating point number, i.e. "50M" and "5e7" will both be displayed as "50MHz" after you select enter. You may also enter the value as a period, i.e. "20n" and "2e-8" will both be displayed as "50MHz".

The minimum clock period available with Vector Output Mode at Full Channel 180Mbit/s is 1MHz. Maximum clock frequency for Full Channel Mode is 180MHz. The minimum clock frequency available with Vector Output Mode at Half Channel 300Mbit/s is 1MHz. Maximum clock frequency for Half Channel Mode is 300MHz.

External Clock Source

Use an external clock source when you want to synchronize the frequency of the output vectors to the system under test. With this mode selected, you do not have direct control over the frequency of the output vectors. Output vector frequency will be the same as the external clock.

When using an external clock source the maximum clock period for the Vector Output Mode at Full Channel 180Mbit/s is 180 MHz. The maximum clock period for the Vector Output Mode at Half Channel 300Mbit/s is 300 MHz.

CAUTION: If the external clock is faster than the maximum period, the Agilent 16720A

will produce erroneous output vectors.

Clock Out Delay

The clock out delay setting lets you position the output clock with respect to the data. The zero setting is uncalibrated and should be measured to determine the initial position with respect to the data.

Chapter 1: Using the Agilent Technologies 16720A Pattern Generator

Overview of the Agilent Technologies 16720A Pattern Generator

Each numerical change of one on the counter results in an approximate change of 500 ps.

Building a Sequence of Test Vectors

Test vectors determine the pattern output at each clock cycle. Test vectors are positioned in a list called a sequence. When a sequence is run (see page 16), the list of vectors is executed in order of first vector to last vector. Vectors are always output on the rising edge of the clock.

In every pattern generator application, you have two sequences. An INIT SEQUENCE (initialization sequence) is used to place your circuit or subsystem in a known state. The initialization sequence is followed by the MAIN SEQUENCE. The main sequence is used for the actual pattern generation that stimulates your circuit under test. The INIT sequence is only run once, while the MAIN sequence loops if you select a repetitive run.

Using Hardware and Software Instructions

In addition to test vectors, both INIT and MAIN sequences can include predefined instruction (see page 78) elements. Instructions can create Breaks, Loops, and Wait, and can even signal the Intermodule Bus. The most useful instruction is "User Macro". With a User Macro instruction, you can create reusable sequences that accept parameters. This flexibility is very useful in prototype turn-on and environmental testing.

For more information on INIT and MAIN sequences and how to create them, see the following topics.

“Building an Initialization Sequence” on page 21

“Building a Main Sequence” on page 23

“Building a User Macro” on page 25

“Working with Instruction Types” on page 78

Chapter 1: Using the Agilent Technologies 16720A Pattern Generator

Overview of the Agilent Technologies 16720A Pattern Generator

Running the Pattern Generator

If you are not changing the run options, simply select the Run icon to run a measurement. Select the Stop icon to stop a measurement.

See Also “What Happens when Run is Selected” on page 16

“What Happens when Stop is Selected” on page 16

What Happens when Run is Selected

In single run mode, the vectors are output from the first vector in the initialization sequence to the last vector of the main sequence. The last vector of the main sequence will be held at the outputs until you run again.

In repetitive run mode, the vectors in the initialization sequence will be output from first to last, one time, then the main sequence will repetitively output the vectors in that sequence until you select the Stop icon.

What Happens when Stop is Selected

When the pattern generator acknowledges stop, the vector currently being output will be held at the outputs until you run again.

Chapter 1: Using the Agilent Technologies 16720A Pattern Generator

A Beginner’s Exercise

This exercise begins with the pattern generator Format tab active. If it is not active, select Format in the pattern generator window now.

In this exercise, you will create a label with eight output channels assigned to it. You will then create a "Walking Ones" output pattern using one of the automatic pattern fill functions.

NOTE: This exercise does NOT require you to connect the probes or view the output.

The intent of this exercise is to give you practice configuring the pattern generator interface. A timing analyzer display of the results is furnished for you.

1. Configure Format (see page 17) with a label called "Walk1" and all eight bits of Pod 6 assigned.

2. Select Sequence.

3. Configure Sequence (see page 18) with a Walking Ones sequence.

4. Set up the Workspace. (see page 19)

5. View the results. (see page 19)

Configure Format

1. In the pattern generator’s Format area, select the label Label1, then select Rename. In the Rename dialog, enter "Walk1", then select OK.

2. Select the bit assignment field under Pod 6 and select the menu item with all eight bits set to "*" (on).

Chapter 1: Using the Agilent Technologies 16720A Pattern Generator

A Beginner’s Exercise

Configure Sequence

1. In the pattern generator’s Sequence window, select Hex and set the numeric base to Binary.

2. Select the first sequence line. This positions the cursor.

3. Select Rotate, and configure the Rotate Pattern Fill dialog as shown. Select Fill.

4. Select Close.

Chapter 1: Using the Agilent Technologies 16720A Pattern Generator

A Beginner’s Exercise

Set up the Workspace

1. Open the system Workspace window.

2. Drag and drop a waveform icon onto the pattern generator icon.

3. Select the waveform icon, then select Display.

4. Select the Run icon.

View the Results

1. Select Walk 1 all in the waveform display, then select Expand.

2. Set the Samples/div to 1.

Chapter 1: Using the Agilent Technologies 16720A Pattern Generator

A Beginner’s Exercise

Chapter 1: Using the Agilent Technologies 16720A Pattern Generator

Building an Initialization Sequence

The initialization (INIT) sequence is the first of two vector sequences that appear in the Sequence display. Use the INIT sequence to put the circuit or subsystem into a known starting condition. You can also use the INIT sequence to arm a logic analyzer or oscilloscope with the Signal IMB instruction to begin a measurement when the MAIN sequence begins. If you leave the INIT sequence empty, it will be ignored.

What Happens when Run is Selected

Building the INIT Sequence

The INIT sequence can contain hardware and software instructions (see page 78) as well as vector data. However, instructions are not allowed on the first two vector lines.

1. Select the Sequence tab, then select INIT START.

2. Select Insert After, then select Vector.

3. Repeat for each new vector line you want to insert.

4. Select the left-most character in the new vector line.

5. Select Edit.

6. Enter in the desired vector data. As you enter the information, the default cursor wrap (see page 113) setting will roll the cursor left-to-right and top line to bottom line.

Chapter 1: Using the Agilent Technologies 16720A Pattern Generator

Building an Initialization Sequence

7. Optional - If applicable, insert an instruction (see page 78) instead of entering vector data.

See Also “Working with Labels and Pods” on page 85

“Editing Sequences” on page 73

“Working with Instruction Types” on page 78

“Building a User Macro” on page 25

“Automatic Cursor Wrap” on page 113

Chapter 1: Using the Agilent Technologies 16720A Pattern Generator

Building a Main Sequence

The MAIN sequence is the second of two vector sequences that appear in Sequence. Use the MAIN sequence as the primary signal generation sequence. The MAIN sequence must contain at least two vectors to output.

What Happens when Run is Selected

Building the Main Sequence

The MAIN sequence can contain hardware and software instructions (see page 78) as well as vector data. However, instructions are not allowed on the first two vector lines or the last vector line.

1. Select the Sequence tab, then select MAIN START.

2. Select Insert After, then select Vector.

3. Repeat for each new vector line you want to insert.

4. Select the left-most character in the new vector line.

5. Select Edit.

6. Enter in the desired vector data. As you enter the information, the default cursor wrap (see page 113) setting will roll the cursor left-to-right and top line to bottom line.

7. Optional - If applicable, insert an instruction (see page 78) instead of entering vector data.

Chapter 1: Using the Agilent Technologies 16720A Pattern Generator

Building a Main Sequence

See Also “Working with Labels and Pods” on page 85

“Editing Sequences” on page 73

“Working with Instruction Types” on page 78

“Building a User Macro” on page 25

“Automatic Cursor Wrap” on page 113

Chapter 1: Using the Agilent Technologies 16720A Pattern Generator

Building a User Macro

A User Macro is a vector sequence defined by a custom name, then inserted by name into a sequence wherever the macro is needed. Macros may be inserted into the INIT or MAIN sequences of the vectors in Sequence, or into other macros. Using macros gives you the benefit of keeping INIT or MAIN sequences generic. By simply interchanging macros, you change the pattern generator output.

NOTE: Care should be taken to avoid infinite loops. For example, if macro 0 calls

macro 1, and macro 1 calls macro 0, this will cause an infinite loop.

Macros can also accept parameters (see page 98). A major benefit in using parameters is that you keep a macro’s functionality generic and still direct specific action identified by parameters. Think of a parameter as the only part of a macro that changes as the macro is reused. Each macro can accept a maximum of 10 unique parameters.

Typically, you create a macro first under the Macro tab, then insert it into sequences under the Sequence tab. You can create 100 different macros for use in one or more pattern generator sequences.

Differences between User Macros and the INIT and MAIN sequences are that macros cannot use any instruction that interacts with the intermodule bus (IMB). The reason is that these instructions can only be included once into the sequence. Since macros may be called as many times as desired, allowing these instructions within macros would violate this restriction. You remove macros from sequences by using the Delete Line(s) function.

Creating the Macro

A macro sequence can contain hardware and software instructions (see page 78) as well as vector data. However, instructions are not allowed on the first vector line.

1. In Macro, recall (see page 114) the macro that you want to create.

2. Select MACRO START.

3. Select Insert After, then select Vector.

Chapter 1: Using the Agilent Technologies 16720A Pattern Generator

Building a User Macro

4. Repeat for each new vector line you want to insert.

5. Select left-most character in the new vector line.

6. Enter in the desired vector data. As you enter the information, the default cursor wrap (see page 113) setting will roll the cursor left-to-right and top line to bottom line.

7. Optional - Insert an instruction (see page 78) instead of entering vector data.

8. Enter in a name for the new macro.

9. Optional - Select Parameters and turn on any parameters you plan to use.

Inserting the Macro

1. In Sequence or Macro, select the vector line directly above where you want to insert the User Macro instruction.

2. Select Insert After, then select User Macro.

3. Select the User Macro instruction.

4. From the Macro Selection dialog that appears, select the desired macro name you want to insert.

5. Select OK.

Chapter 1: Using the Agilent Technologies 16720A Pattern Generator

Building a User Macro

NOTE: See The User Macro Instruction (see page 81) for restrictions on User Macro

instruction usage.

See Also “Recalling Macros” on page 114

“Copying Macros” on page 115

“Working with Macro Parameters” on page 98

“Working with Instruction Types” on page 78

“Editing Sequences” on page 73

“Working with Labels and Pods” on page 85

Chapter 1: Using the Agilent Technologies 16720A Pattern Generator

Importing Agilent 16522A ASCII Files

You can create an ASCII text file and import it as a complete pattern generator program. In general, the ASCII file consists of a block of setup information, a block of label and channel information, and a block of pattern generator vector data. The file must be saved in ASCII format and organized as shown in step 1 of the procedure below.

1. Create the ASCII file (see page 30) in a text editor.

2. Save the file as Te x t On l y or ASCII Format in a directory on your analyzer’s hard drive.

3. In the Sequence menu bar, select File, then Import 16522A ASCII File. See the caution below.

4. From the file selection dialog that appears, select the desired path and ASCII file name.

5. Select Import.

CAUTION: Importing an Agilent 16522A ASCII file causes all current Format and

Sequence information to be overwritten. Be sure to save the pattern generator configuration before you begin the import process.

NOTE: Importing a 1048576 line 16522A ASCII file may take approximately two

minutes. If a 1048576 sequence is in memory when you begin an import, it may take up to a minute to clear the current data and up to two minutes to import the new data.

Chapter 1: Using the Agilent Technologies 16720A Pattern Generator

Importing Agilent 16522A ASCII Files

This figure shows Format after the ASCII file example shown in step 1 was imported.

Chapter 1: Using the Agilent Technologies 16720A Pattern Generator

Importing Agilent 16522A ASCII Files

Creating an ASCII File

You can create an ASCII file using any Windows, MS-DOS, or UNIX text editor. An ASCII file consists of a file identifier and three blocks of information. Each block must follow the specified order.

• ASCII 000000 - required file identifier ("ASCII" followed by 5 spaces and 6 zeros). ASCDown - optional. Retained for backwards compatibility.

• 1st block (optional)

FORMat - clock, channel mode, and delay information.

• 2nd block

LABel - names and number of channels.

• 3rd block

VECTor - vector data and Repeat indicators.

File Requirements and Precautions

• The file must contain only specified pattern generator commands (see page 32), and in the order and format shown in the example below.

• The file must be saved in "ASCII" or "text only" format.

• Vector data is assumed to be entirely hexadecimal base.

• No pattern generator instructions are allowed in the data.

• No pattern generator macros are defined or invoked in the data.

• All labels consist of adjacent bits.

• The file must end with a line termination character (line feed "<lf>" or a

carriage return and line feed "<CR><lf>".

• Comments can be included after the first line (ASCII 000000). Comments begin with a slash '/' and terminate at the end of the line.

+ 102 hidden pages

Agilent 16720A Help Volume

Specifications and Main Features

Frequently Asked Questions

User Manual

Using the Agilent Technologies 16720A Pattern Generator

Contents

Using the Agilent Technologies 16720A Pattern Generator

Overview of the Agilent Technologies 16720A Pattern Generator

Mapping Probe Pods to the Interface

Vector Output Mode

Clock Source

Building a Sequence of Test Vectors

Running the Pattern Generator

What Happens when Run is Selected

What Happens when Stop is Selected

Configure Format

Configure Sequence

Set up the Workspace

View the Results

Building an Initialization Sequence

Building a Main Sequence

Building a User Macro

Importing Agilent 16522A ASCII Files

Creating an ASCII File