176
Development Tools User’s Guide
Intel
®
IXP2400/IXP2800 Network Processors
Performance Monitoring Unit
The random number generator used in RBS is a 16-bit Linear Feedback Shift Registers (LFSR).
The equation used for determining the average period produced is as follows:
Period = ½ (2
6
*2
R
)/F + W
where:
R = Random Range
F = CPU Frequency
W = Programmed Window
3.4
PMU Graphical User Interface (GUI)
The PMU is started from the Developer’s Workbench and appears as a series of property pages.
These property pages are used for selecting a previously created canned analysis or for configuring
a new test. Each property page has its own notion of what the experiment is. Pressing the
Run
button activates the experiment from whichever property page tab is currently selected (i.e., on top)
on the GUI.
On the Canned Analysis property sheet, pressing the
Load
button or "loading" an experiment
copies that experiment to the appropriate other sheet (e.g. TBS or RBS). Of primary significance
here is that if you load an experiment, select the TBS tab (for example), change the experiment,
switch back to the Canned Analysis tab, and then press the
Run
button, you will run the "original"
experiment, not the modified one. You would have to have the TBS sheet active (i.e., on top) when
you press the
Run
button to use the modified parameters.
So in summation the Canned Analysis property page is used to run a previously-saved experiment
without modification, while the TBS and EBS property pages are used to create, modify, or run
experiments.
To run the PMU:
1. Go to the Developer’s Workbench and open a project and
begin Debugging.
2. Select
Hardware -> Performance Monitoring
.
3. The Performance Monitoring Unit GUI is displayed (see