Dynamic DC Leakage Current Path Check (dyn_dcpath)

Spectre Syntax

title dyn_dcpath net=[n1 n2 ...] duration=<value> ith=<value> time_window=[start1 stop1 start2 stop2 ....] <save=no|violation> <spice=no|yes> <leaki_times=[t1 t2 …]> <xinst=[xinst1 xinst2...]> error_limit=<value> <sort=no|current>

SPICE Syntax

.cck title dyn_dcpath net=[n1 n2 ...] duration=<value> ith=<value> time_window=[start1 stop1 start2 stop2 ....] <save=no|violation> <spice=no|yes> <leaki_times=[t1 t2 …]> <xinst=[xinst1 xinst2...]> error_limit=<value> <sort=no|current>

Description

Reports the conductance paths between user-specified nets. The check is based on transient analysis and reports th qualifying paths carrying an absolute current higher than the parameter ith for a duration longer than the specified duration, within the specified time_window. If you specify leaki_times, Spectre FX treats it like a special time window with only one time point.

If more than two nets are specified, Spectre FX checks the leakage path between each net combination. For example, if net=[vdc1 vdc2 0] is specified, then the conducting path between vdc1 and vdc2, vdc1 and 0, and vdc2 and 0 is checked.

The results are written to a file with the extension dynamic.xml.

Arguments

net	Hierarchical node names between which the leakage path is checked. Wildcarding is not allowed. All combinations of nets are checked. Default is none.
duration	Leakage paths with a duration longer than specified value are reported (default is 5ns).
sort	If set to no, sorting is not performed. If set to current, the violations are sorted by max current. Possible values are no and current. The default value is no.
ith	Leakage paths with absolute current higher than the specified value are reported (default is 50uA).
time_window	Time window to which the circuit check is applied. Multiple non-overlapping time windows are supported. Default time window is 0 to tend.
save	Specifies how to probe the signals specified within this circuit check. Possible values are: no: None of the signals in this circuit check are probed. This is the default value. violation: Automatically probe the signals with violations under this circuit check.
spice	Specifies whether to save the probed signals specified by the save parameter in the SPICE syntax. Possible values are: yes: Saves the signals in SPICE syntax no: Saves the signals in Spectre syntax. This is the default value.
leaki_times	Defines the times at which the check is performed.
xinst	Subcircuit instances to be excluded from the check. Default is none.
error_limit	Maximum number of errors to be reported. Default is 10000.

Example

Spectre Syntax

dcpath1 dyn_dcpath ith=200u net=[vdd 0] duration=1n time_window=[1n 20n]

SPICE Syntax

.cck dcpath1 dyn_dcpath ith=200u net=[vdd 0] duration=1n time_window=[1n 20n]

The above command will report the DC conductance path between vdd and 0. The command will report the paths that carry current higher than 200u for a duration longer than 1n within the time window between 1n and 20n. The following is an example of the report that is displayed in the Web browser:

The path report has three sections. Each section is explained below.

• The first section shows that a path is found starting from net vdd to net 0. Since this is a check based on transient-analysis, the name of the table is Dynamic dcpath check based on transient analysis.
• The second section shows the actual instances in the path. The first column Instance contains instances in the path. The second column contains the current through the instances. The current is taken at the end of violation, that is, at 1.52e-8 seconds (start + duration = 1.03e-8 + 4.94e-9).
• The third section shows the state of MOSFETs in the path. It does not report anything other than MOSFETs. The first column Instance Name is the MOSFET name. The second column is the model name. The following columns are the terminal names and voltages. The last two columns show the drain and source terminal currents. The values are taken at the end of violation.

Similar to the XML report, the text report is shown below:

Related Topics

Dynamic Checks

Return to top