The Real-Time Tuning (RTT) assistant is one of the most powerful features of ADE Explorer that helps you fine-tune your design without the need to run simulations repeatedly. It is equipped with simple and easy-to-use graphical user interface that lets you change the design variables and parameter values and also view the updated results simultaneously.
While working with the RTT assistant, you may want to reconfigure the look and feel of the assistant and change other settings according to your requirements. There are some very useful environment variables that you can set to make things work in your own customized way. Let's know more about them.
Did You Say 'It's Timeout'?
Consider the scenario where you're working with the RTT assistant and you forget to turn off the RTT assistant after your work is done. Now, as the RTT assistant is open, a simulator license remains checked out and it's clearly visible that the simulator is unnecessarily blocked, whereas it could be of use to someone if you're working on shared resources.
So, to avoid keeping a simulator license checked-out when the RTT assistant is inactive for a long time, and to maximize the resource utilization, you can specify a timeout value by setting the activeTimeout environment variable in your .cdsinit file or CIW:
envSetVal("maestro.rtt" "activeTimeout" 'int "3600")
When the RTT assistant is inactive for longer than the specified timeout value, the simulator license gets checked in and the RTT simulation is stopped. Note that the default timeout value is 3600 seconds.
Can I View the Status of My RTT Simulations?
Do you know 10 seconds after running simulations, the RTT assistant displays a log file that shows the latest simulation status? Is your simulation so fast (less than 10 seconds) that you don’t get to see the log file? Or, you might not be worried about the log file because the RTT simulations are likely to be quicker. But, if you are really interested in knowing the latest status of the current RTT simulation run, you can set the time using the timeoutShowLog environment variable. This variable controls the time after which the log file is popped up when you hit the Play (start simulation) button in the RTT assistant.
envSetVal("maestro.rtt" "timeoutShowLog" 'int "10")
The default value for this variable is 10 seconds. If you set it to a negative value, the log file will not be displayed. This variable is useful when the RTT simulation run is long.
I’ve Got Some Dependent Variables. How Will They Work in RTT?
If you have dependencies within the variable and parameters in the setup, then you would surely want to know the answer to this question. Well, the answer is: you can control the dependency between variables and parameters in RTT mode by setting the keepVariableDependency variable to t. If you set this variable to nil, the dependency will not be considered and you can tune the dependent values separately. The default value of this variable is t, which means that the dependency is always honored.
envSetVal("maestro.rtt" "keepVariableDependency" ’boolean t)
I Don't Want to See Too Many Sliders in the RTT Assistant...
If you are particular about keeping your screen-space uncluttered and want things to show up only when you need to use them, then the sliderOnMouseOver variable is of your interest. You can set this variable to t, which is the default value, to display the tuning slider for variable and parameters when you mouse-hover or click a variable or parameter. When you set this variable to nil, tuning sliders for all variables and parameters are displayed in the RTT assistant.
envSetVal("maestro.rtt" "sliderOnMouseOver" ’boolean t)
Start my RTT Simulations Quickly, Please!
Are you pressed for time and want your RTT simulation runs to start as quicker as possible? Then, you can set the simulateOn environment variable, which specifies an event to control the time lag between changing the variables and parameter values, and running the RTT simulation. By default, this variable is set to onMouseUp event, which means the simulation will be started as soon as the mouse button is released on the slider.
envSetVal("maestro.rtt" "simulateOn" ’cyclic "onMouseUp")
Note that you can also set it to other valid values:
- adaptiveDelay: It’s mostly used for very fast simulation runs where you would not like to wait for even half a second for the simulation to start. When this value is set, the run time from the first simulation run is evaluated and set as the delay time for the subsequent simulation runs.
- 500ms: If you specify the value as 500ms or 0.5s, the new simulation will start after the specified time.
Related Resources
If you would like to know more about real-time tuning and the related environment variables, their default and valid values, see the below links:
- Virtuoso ADE Explorer User Guide
- Video
- Blog
For more information on Cadence circuit design products and services, visit www.cadence.com.
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