Stats

  • Locked Locked
  • Replies 14
  • Subscribers 90
  • Views 23017
  • 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

SDC file-HOLD and Setup Time

archive

Hi,
I am just starting using the nano encounter tool. I just wonder if the sdc file we give to the encounter tool should be the same as SDC file we give to the RTL compiler?
I want to connect my synthesized block to a memory with specific setup hold time. Does anyone has an idea how to give the encounter tool the specific setup time and hold time? how to put a constrain on its output and input port for setup and hold time?

Thanks,

Houman
 


Originally posted in cdnusers.org by houmanh
Parents

  • The semantics to  set_output_delay -min   are   (IMHO) inverse from what
    one might expect .

    If you were to picture the set_output_delay -min contraint as as the hold check on
    a flip-flop in the fanout of the output port, you would assume that a positive value
    would make the check more conservative - this is  not the case.

    The value specified for set_output_delay -min is subtracted from the clock
    edge. If the value is positive, then the required time is earlier, and
    hence the slack is increased.

    A negative set_output_delay min means that the data is required to stick
    around past the reference clock - which decreases the slack.

    The polarity of hold check values in .lib and those specified in set_output_delay -min
    are not the same.



    Originally posted in cdnusers.org by ejm
Reply

  • The semantics to  set_output_delay -min   are   (IMHO) inverse from what
    one might expect .

    If you were to picture the set_output_delay -min contraint as as the hold check on
    a flip-flop in the fanout of the output port, you would assume that a positive value
    would make the check more conservative - this is  not the case.

    The value specified for set_output_delay -min is subtracted from the clock
    edge. If the value is positive, then the required time is earlier, and
    hence the slack is increased.

    A negative set_output_delay min means that the data is required to stick
    around past the reference clock - which decreases the slack.

    The polarity of hold check values in .lib and those specified in set_output_delay -min
    are not the same.



    Originally posted in cdnusers.org by ejm
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.