Jump to content

Recommended Posts

regarding clause  7.1.1.c

"state values are not supported. If 4-state values are passed into the PSS model via the procedural interface (PI) (see 17.2), any X or Z values are converted to 0."


To my understanding PSS is meant for hardware verification. how can that be done without even the most basic x-propagation test options open?

Share this post

Link to post
Share on other sites

You're correct that PSS is intended for hardware verification -- specifically targeted at the transaction and higher level of abstraction. 4-state modeling typically applies at the signal level, and doesn't propagate up to transaction level and above.

I double-checked, and the SystemVerilog LRM specifically restricts randomization to 2-state values:

"Constraints support only 2-state values. The 4-state values (X or Z) or 4-state operators (e.g., ===, !== ) are illegal and shall result in an error."

Hope this helps!

Share this post

Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now