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AR# 7560

XPLA Professional - Generating a simulator clock with a delayed starting time.


Keywords: XPLA, Professional, CoolRunner, fitter, clock, delay, simulator,
functional, timing

Urgency: Standard

General Description:
How do I generate a clock in the simulator that has a delayed starting time?


To create a clock that has a delayed starting time and then maintains
a regular duty cycle (50% in this case) from then on, follow these steps:

1.After you compile the design, click the "FunSim..." button and the
XPLA Professional software will display waveforms.
2.Create the stimulus you need and the reference clock.
3.Click the "Save" button and XPLA Professional software will create
two files, [design].scl and [design].net where [design] is your
design name.
4.Edit the [design].scl file so that the statements for the reference
clock (CLK1) and the out-of-phase clock (CLK2) look something
like this (please note the spacing):

S 1 (50, 100, ETC) CLK1
S 1 (TIME=25: 50, 100, ETC) CLK2

In the above two statements, CLK1 starts with the value of '1' and
transitions every 50nS. CLK2 starts with the value of '1' and after
25ns, it begins to transition every 50nS. This will result in CLK2
being the same frequency as CLK1, but because of the delayed
starting time (TIME=25:), CLK2 will be out-of -phase with CLK1. You
may need to adjust these numbers to match the frequency and phase
shift that you need.
5.From the directory in which you have XPLA Professional installed,
(typically C:\XPLA), copy the file xpla.lib into your design directory.
6.Open a DOS window and change the directory to your design
7.From the DOS prompt, execute the following commands:

(this will generate .bin)
c:\xpla\simnet3 [design].net
where "xpla" is the location of your XPLA Professional software and
[design] is your design file name. Please note the spacing.

(this will generate .scr)
c:\xpla\simscl3 [design].bin [design].scl

(this will generate .res)
c:\xpla\simrun3 [design].bin [design].scr

8.You now have a file [design].res that shows the results of the
simulation. Open the functional simulator by pressing the "FunSim..."
9.At this point you may get an error message saying "SCL Not
Recognized". Press the "OK" button and the ASCII version of the
[design].scl file will open. If this occurs just close the editor window.
10.In the simulator user interface, click File | Open and select
[design].res and you can see the results.
AR# 7560
Date 03/28/2001
Status Archive
Type General Article