PDNSim¶

PDNSim is an open-source static IR analyzer.

Features:

Report worst IR drop.
Report worst current density over all nodes and wire segments in the power distribution network, given a placed and PDN-synthesized design.
Check for floating PDN stripes on the power and ground nets.
Spice netlist writer for power distribution network wire segments.

Commands¶

set_pdnsim_net_voltage -net <net_name> -voltage <voltage_value>
check_power_grid -net <net_name>
analyze_power_grid -vsrc <voltage_source_location_file> \
                   -net <net_name> \
                   [-outfile <filename>] \
                   [-enable_em] \
                   [-em_outfile <filename>]
                   [-dx]
                   [-dy]
                   [-em_outfile <filename>]
write_pg_spice -vsrc <voltage_source_location_file> -outfile <netlist.sp> -net <net_name>

Options description:

vsrc: (optional) file to set the location of the power C4 bumps/IO pins. Vsrc_aes.loc file for an example with a description specified here.
dx,dy: (optional) these arguments set the bump pitch to decide the voltage source location in the absence of a vsrc file. Default bump pitch of 140um used in absence of these arguments and vsrc
net: (mandatory) is the name of the net to analyze, power or ground net name
enable_em: (optional) is the flag to report current per power grid segment
outfile: (optional) filename specified per-instance voltage written into file
em_outfile: (optional) filename to write out the per segment current values into a file, can be specified only if enable_em is flag exists
voltage: Sets the voltage on a specific net. If this command is not run, the voltage value is obtained from operating conditions in the liberty.

Example scripts¶

See the file Vsrc_aes.loc file for an example with a description specified here.

Regression tests¶

Limitations¶

FAQs¶

Check out GitHub discussion about this tool.

Cite this Work¶

If you find PDNSim useful, please use the following bibtex to cite it:

@misc{pdnsim,
author = "V. A. Chhabria and S. S. Sapatnekar",
title={{PDNSim}},
note= "\url{https://github.com/The-OpenROAD-Project/OpenROAD/tree/master/src/PDNSim}"
}

License¶

BSD 3-Clause License. See LICENSE file.

Table Of Contents

PDNSim

Elements of a configuration file

Voltage source location file description