Static NMOS to VDD Count Check (static_nmos2vdd)

Spectre Syntax

title static_nmos2vdd node=[n1 n2 ...] count=<value> <inst=[inst1 inst2...]> <xinst=[xinst1 xinst2...]> <subckt=[subckt1 subckt2....]> <xsubckt=[xsubckt1 xsubckt2....]> <depth=n> error_limit=<value>

SPICE Syntax

.cck title static_nmos2vdd node=[n1 n2 ...] count=<value> <inst=[inst1 inst2...]> <xinst=[xinst1 xinst2...]> <subckt=[subckt1 subckt2....]> <xsubckt=[xsubckt1 xsubckt2....]> <depth=n> error_limit=<value>

Description

Counts unpaired NMOS in the charging path from a fanout node to VDD and reports paths having NMOS count greater than the specified count

The check only analyzes the fanout nodes. It does not check the nodes connecting only to MOSDIODEs or MOSCAPs.

The check counts NMOS from a fanout node to VDD. It does not include NMOS in the count under the following conditions but does report them.

• it is connected to vdd
• it is connected parallel to PMOS as in a transmission gate
  
  

The results are written to the static.xml file, which can be viewed in a Web browser.

Arguments

node	Nodes to which the check is applied. Default is none.
count	Maximum number of permitted NMOS. Default is 3.
inst	Subcircuit instances to which the check is applied. Default includes all instances (inst=*).
xinst	Subcircuit instances to be excluded from the check. Default is none.
subckt	The instances of the specified subcircuit to which the check is applied. Default includes all subcircuits (subckt=*).
xsubckt	The instances of the specified subcircuits that are excluded from the check. Default is none.
depth	Hierarchy levels (starting from top, instance, or subcircuit scope) to be checked. Default is 8.
error_limit	Maximum number of errors reported. Default is 10000.

Example

Spectre Syntax

chk1 static_nmos2vdd node=[*] count=1 

SPICE Syntax

.cck chk1 static_nmos2vdd node=[*] count=1

The above statement reports all paths from all fanout nodes having NMOS count greater than 1. The following is an example of the report that is displayed in the Web browser:

It reports one path from fanout n3 to vdd. The number of NMOS found in this path is two. Note that mp1 is a PMOS therefore does not contribute in the count.

Related Topics

Static Checks

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