Generate PI-2005 Stimulus Vectors
WaveFormer Pro and TestBencher Pro generate stimulus files for Pulse Instruments PI-2005 Pattern Generator.
Programming a pattern generator with enough stimulus to adequately exercise a hardware prototype has
traditionally been a very labor intensive and error prone process. SynaptiCAD's WaveFormer Pro eliminates
this problem by allowing the reuse of waveforms from the simulation phase to serve as the waveform stimulus.
WaveFormer also has a built in timing diagram editor that lets you create and edit the pattern generator
stimulus. WaveFormer exports the waveforms as displayed in the timing diagram window. TestBencher supports
repeat loop markers that will cause a section of the waveform data to be repeated by the pattern generator.
Timing Diagram Editing Environment
In addition to direct translation, WaveFormer can generate stimulus waveforms using a combination of
graphically drawn signals, timing parameters that constrain waveform edges, clock signals, and temporal
and Boolean equations for describing complex, quasi-repetitive signal behavior. Advanced operations
on signals such as time scaling and shifting, and block copy and pasting of signal behavior over an
interval of time are also supported. This simple, but powerful environment dramatically eases the labor
associate with the generation of complex stimulus. The resulting hardware test benches also have the
same functional coverage of the simulation models ensuring that the hardware prototype is adequately
Instructions for Creating PI-2005 Files
WaveFormer Pro and TestBencher use a timing diagram define the waveforms for export. Waveforms can be
imported from simulation files or drawn in the timing diagram editor. Each timing diagram should contain
one clock. The positive edges of the clock will be used as the sampling points for rest of the waveforms.
The period of the clock will be output to the PERIOD statement in the PI-2005 file. By default,
WaveFormer will use the first clock in the timing diagram as the sampling signal. If you import waveforms
from a simulation file you will need to either add a clock or convert the clocking signal to a SynaptiCAD
clock by right clicking on the signal name and choosing Signal <=> Clock from the context
The PI-2005 requires that waveform values be only 0's and 1's. So the export script converts non-binary
waveform values like tri-state into 1's during the export. Also the PI-2005 only supports time units
of NS, US, and MS for the PERIOD statement. This means that the display
time unit for the timing diagram should be set to one these three values.
Data is loaded serially one channel at a time into the PI-2005. The signals in the timing diagram are
mapped to the channels in the PI-2005 using the Edit Pod Properties dialog. PI-2005 channels
start with #1 and use Pod0. You must setup Pod0 so that the maximum pod bits is 64 and the offset is
TestBencher supports repeat loop markers in the export of PI-2005 data. Each repeat loop defines a subpattern
in PI-2005 file. The smallest subpattern supported by the instrument is 20 clock units long, so each
repeat loop should span at least 20 clock pulses. Repeat loops are ignored by WaveFormer Pro.
WaveFormer and TestBencher Pro Instructions
- In WaveFormer or TestBencher, either load in a simulation file or create a timing diagram.
Each timing diagram must have a clock signal that will be used as the sampling clock. At each rising
edge of the clock, the states of each signal will be written out to the pattern generator file. The
first clock in the timing diagram will be assumed to be the sampling clock, all other clocks will be
- To draw the above diagram, press the Add Clock and Add Signal buttons to
add the clock and signals. Grid lines can be added to the clock by double clicking on the clock name
to open a clock properties dialog, press the Grid Lines button to open the grid dialog, and then
check the Enable Grid Lines check box.
- Left click in the waveform window to draw the waveforms. To make busses, double click
on the signal name and set the MSB and LSB. The HEX button is used to add bus values to the waveforms
- If you have imported a simulation file you must mark one signal as the clock. Right click
on the signals name can choose Signals <=> Clock from the context menu.
- Choose Export > Edit Pods menu to open the Edit Pods dialog and set the
maximun pod bits to 64 and the offset to 1.
- Press the three buttons in this order, Clear Mappings, Map Empty Signals,
and Offset Pod Bits. Check to make sure that the first signal mapping is on POD0 and Channel
1. All the other signals should be mapped to POD0.
- Press OK to close the dialog.
- Choose the Export > Export Timing Diagram As menu option to open the file dialog.
- Choose PI-2005 Pattern Generator from the file type drop-down list box.
- Enter a file name and click the OK button to close the dialog. This will save
the file and also display the results in the Report window. It should look something like:
; Generated by TestBencher Pro
LOAD CHANNEL 1 ;(SIG0)
LOAD CHANNEL 2 ;(SIG1)
LOAD CHANNEL 3 ;(SIG1)
LOAD CHANNEL 4 ;(SIG1)
***** More channel code ***********
LOAD CHANNEL 16 ;(SIG8)
DEFINE SP 1 (1-24)
50 BEGIN 1
51 SP 1 * 1
PERIOD 100.00000000000003 NS
PI-2005 Pattern Generator Instructions
The resulting text file is a series of GPIB commands that can be read directly by the PI-2005 pattern
generator. Contact Pulse Instruments, [email protected], for details on custom application
development and working directly with the instrument. The exported text file can also be imported into
the PI-PAT control software.
PI-PAT is the control software and pattern editor for the PI-2005:
- In the PI-PAT software, create a new PI-2005 document via File > New.
- Choose File > Import File menu and select the exported text file.
- Once the pattern file has been imported, PI-PAT may then be used to control the pattern
generator and to edit the waveform patterns.
For more information about Pulse Instruments PI-2005 pattern generator visit their web site at