1.10 Base and Display Time Units

The Base Time Unit sets the smallest amount of time that can be represented in the program. The Display Time Unit sets the units of all times displayed and entered. Normally the base time unit is a magnitude smaller than the display time unit. This gives you the ability to specify exact values while allowing most other numbers to be entered at a convenient level.

The program has a limit of approximately 1 billion time units (varying with screen resolution and size). For this reason the base time unit should be chosen to match the range of times needed by your design.

To set the Base Time Unit:

•Select the Options > Base Time Unit menu to open the Base Time Unit dialog.

•Select the new base time unit by clicking the proper radio button (fs, ps, ns, us, ms).

•Next, decide how the existing values in the project will convert to the new base time unit. For example, if you change from ns to ps then:

•Keep All Times makes an existing 5ns into 5000ps (the same time value);

•Scale All Times does not change the numbers but it changes their meaning (5ns will now become 5ps);

basetimeunit_dlg

•Scale Parm Times, Keep Signal Times is a combination of the other two methods.

To set the Display Time Unit:

•Choose the Options > Display Unit menu item to display a submenu of display time units, and click on a time unit to make it the new Display Time Unit.