AR# 1623: Foundation Simulator: How to assign a value to a bus using Formulas
AR# 1623
Foundation Simulator: How to assign a value to a bus using Formulas
Description
To assign a value to a bus in the Foundation Simulator, you may apply a Formula to the bus.
The value you wish to assign should be placed in brackets, [] and the value is in Hex. If you specify a value of [4], and assign is to an 8-bit bus, the upper 4 bits of the bus will be driven to 0.
Up to 16 Formulas can be defined as "Formula LEDs". These formulas are accessed through the Stimulator Selection Window. Formula LEDs are always applied starting at time 0ns.
Additional Formulas can be defined in the Formula Editor, and are accessed through the Formula Insert and Formula Replace dialogs. These Formulas can be applied to the bus starting at any simulation time, and can be concatenated to create longer Formulas.
解决方案
1
To define a Formula LED and assign it to a bus, follow this procedure:
1. Open up the Stimulator Selection Window (Stimulator-> Add Stimulators).
2. Click on the Formula... button.
3. Select a Stimulator by double-clicking on it. It will now show the Selected Stimulator in the upper-right field.
4. Enter the formula in the Formula field.
For example, to assign a constant value of 4, the following Formula would be used: [4]
To assign incrementing values to the bus, which increment every 20ns, use this formula: [1]20[2]20[3]20
For more information on proper Formula syntax, please refer to the Foundation Online Documentation.
5. After you have typed in the Formula, click 'Assign Formula'. The Formula will now show up in the 'Defined Assignments' list.
6. Now, to assign this formula to the bus, select the Bus in the Waveform Viewer, and then click on the appropriate Form button in the Stimulator Selection box. For example, if you assigned the Formula as Stimulator F1, then click on the 2nd square from the right on the Form: line in the Stimulator Selection box.
2
To define a Formula and assign it to a bus using the Formula Editor, follow this procedure:
1. Select Waveform -> Formula -> Edit. This opens the Formula Editor.
2. Enter the formula in the 'Enter New Formula' field.
For example, to assign a constant value of 4, the following Formula would be used: [4]
To assign incrementing values to the bus, which increment every 20ns, use this formula: [1]20[2]20[3]20
For more information on proper Formula syntax, please refer to the Foundation Online Documentation.
3. After you have typed in the Formula, click Add. The Formula will now show up in the 'Available Formulas' list.
4. To assign this Formula to a bus, click in the Waveform Viewer to specify both the bus and the time you want the Formula to apply to. Then select Waveform -> Formula -> Insert. Select the Formula and click OK.
5. To concatenate Formulas, click in the Waveform Viewer at the end of the first Formula and insert another formula.
For example, to repeat the incrementing Formula shown above, first click in the Waveform Viewer at time 0ns (next to the bus you want to assign the Formula to). Insert the Formula, which defines the bus from time 0ns up to time 60ns.
Now click on the end of the Formula and insert the same Formula again. Now the bus increments from 1 to 3, then repeats.