Stats

  • Locked Locked
  • Replies 4
  • Subscribers 65
  • Views 15664
  • Members are here 0
This discussion has been locked.
You can no longer post new replies to this discussion. If you have a question you can start a new discussion

Disabling single signals in expression coverage?

cmautner

I am running expression coverage on a design. There are many ATPG multiplexers implemented in RTL, such as

wire signal = aptg_mode ? something : something_else;

Expression coverage complains that, since atpg_mode is always 0 in RTL simulations, the ternary expression is only 50% tested. Is there something I can do about it? Like, a pragma that tells the coverage scoring that atpg_mode is considered to be constant '0'?

Parents

  • Steve,

    thanks for your response.

    Unfortunately it does not seem to help me, since atpg_mode is a signal that is driven from a flop inside the circuit.

    The set_com command appears to apply only to signals that are explicitly constant (assign sig = 1) and not those that simply do not toggle in the simulation.

    But, if set_com would apply to all signals that do not toggle, coverage analysis would report an overly optimistic (aka useless) toggle coverage.

    I really need a way to explicltly list those signals that I want to be ignored.

    thanks!

    christian.

Reply

  • Steve,

    thanks for your response.

    Unfortunately it does not seem to help me, since atpg_mode is a signal that is driven from a flop inside the circuit.

    The set_com command appears to apply only to signals that are explicitly constant (assign sig = 1) and not those that simply do not toggle in the simulation.

    But, if set_com would apply to all signals that do not toggle, coverage analysis would report an overly optimistic (aka useless) toggle coverage.

    I really need a way to explicltly list those signals that I want to be ignored.

    thanks!

    christian.

Children
No Data

Community Guidelines

The Cadence Design Communities support Cadence users and technologists interacting to exchange ideas, news, technical information, and best practices to solve problems and get the most from Cadence technology. The community is open to everyone, and to provide the most value, we require participants to follow our Community Guidelines that facilitate a quality exchange of ideas and information. By accessing, contributing, using or downloading any materials from the site, you agree to be bound by the full Community Guidelines.