How To: Tune DSim Messaging

DSim allows you to control the severity and the maximum count of messages during the compilation and/or simulation. Even when there are no error messages, it is good practice to review all warning messages. You can filter messages and debug your simulation by tuning DSim messaging.

The following command-line options can be passed as arguments to the DSim Cloud CLI (mdc) commands

mdc dsim

mdc dvlcom

mdc dvhcom

See DSim Cloud CLI simulator commands for details. They can be used individually or together to tune DSim messaging.

Tuning Severity

You can tune DSim messaging to satisfy your needs. One strategy to achieve this is:

1. Start your debugging activity from the strict mode, where the bulk of exceptions is flagged as an error.

2. Vet the flagged errors, and determine error-by-error whether they should be demoted to a warning, informational note, or suppressed entirely.

1. Enable the strict mode

To enable the strict mode, use the option

-error warning

which will promote all warnings to errors.

2. Demote a specific error to a warning while in the strict mode

For instance, if you determined that the

=E:[Array] Assignment to static array of different size

error should be demoted to a warning, use the option

-error warning -warn Array

which will promote all warnings to errors and demote any Array error to a warning.

3. Demote a specific error to a note while in the strict mode

For instance, if you determined that the

=E:[Queue] test.sv:100: assignment to invalid index

error should be demoted to an informational note, use the option

-error warning -info Queue

which will promote all warnings to errors and demote any Queue error to an informational note.

4. Suppress a specific error while in the strict mode

For instance, if you determined that the

=E:[$warning call] test.sv:200: from top @ 10

error should be suppressed, use the option

-error warning -suppress '$warning call'

which will promote all warnings to errors and suppress all $warning call errors.

5. Combine message demotions

Once you are done with vetting the flagged errors, you may combine all the desired demotions together. For instance, the previous demotions may be combined together using the option

-error warning -warn Array -info Queue -suppress '$warning call'

For more information on these options, see the Controlling Error Messaging section of User Guide: DSim Common Options.

Setting Max Count of Errors

You can set a maximum count of errors by using the following option

-exit-on-error n

where n shall be a positive integer. The simulation will be terminated once the count of run-time errors reaches the n threshold. For instance, if you wish to terminate the simulation after 10 errors, use the option

-exit-on-error 10

Once the count of run-time errors reaches 10, you will get a fatal error

=F:[LimitReached]:  
  The message limit has been reached  
  10 errors have been found

By default, this capability is not enabled.

This option is available as an argument to the mdc dsim command during run-time of the simulation. See the Error Message Limits section of User Guide: DSim Common Options for more information.

Further Debugging

In addition to the above options to tune DSim messaging, you can debug your simulation using the

-debug-verbose

option. See the Debugging section of User Guide: DSim Common Options for more information.