Stats

  • Locked Locked
  • Replies 1
  • Subscribers 66
  • Views 5782
  • 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

When running upf simulation power net is stuck at 0

2tojohny

I have the following upf constructs:

create_power_domain PD_TOP \

         -include_scope

create_power_domain    PD_V1P8_AVDD \

       -elements { A/B }

create_supply_port NET_V1P8_AVDD \

         -direction in \

         -domain PD_TOP

create_supply_port AGND \

         -direction in \

         -domain PD_TOP

create_supply_net AGND \

         -domain PD_TOP

create_supply_net NET_V1P8_AVDD \

         -domain PD_TOP

connect_supply_net NET_V1P8_AVDD \

         -ports { NET_V1P8_AVDD A/B/AVDD_pin }

connect_supply_net AGND \

        -ports { AGND A/B/AGND_pin }

create_supply_set ss_V1P8 \

         -function { power NET_V1P8_AVDD } \

         -function { ground AGND }

associate_supply_set ss_V1P8 \

         -handle PD_V1P8_AVDD.primary

add_power_state PD_V1P8_AVDD.primary \

        -state ON { -supply_expr {power == \

        `{FULL_ON, 1.8} && ground == `{FULL_ON, 0.0}} \

        -simstate NORMAL}

When I read this upf into xrun, the NET_V1P8_AVDD net/port is always stuck at 0, even if I force it in my testbench.

When:

connect_supply_net NET_V1P8_AVDD \

         -ports { NET_V1P8_AVDD A/B/AVDD_pin }

is commented out, I can force NET_V1P8_AVDD to 1.

It seems UPF is forcing this node to 0.  Where and how to overcome it?

Thanks.

 

  • It sounds like you are having trouble with UPF simulation and the NET_V1P8_AVDD net/port is always stuck at 0, even if you force it in your testbench. When you comment out the line connect_supply_net NET_V1P8_AVDD -ports { NET_V1P8_AVDD A/B/AVDD_pin }, you can force NET_V1P8_AVDD to 1.

    It’s possible that UPF is forcing this node to 0. To overcome this issue, you might try adding a power state for NET_V1P8_AVDD in your UPF file. Here is an example of how to add a power state:

    add_power_state PD_V1P8_AVDD.primary \
    -state ON { -supply_expr {power == `{FULL_ON, 1.8} && ground == `{FULL_ON, 0.0}} \
    -simstate NORMAL}

    This will add a power state for PD_V1P8_AVDD.primary that sets NET_V1P8_AVDD to 1.8V and AGND to 0V.

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.