netchange - format of netchange files read by irsim.
file consists of a series of lines, each of which begins with
a key letter. The key letter beginning a line determines how the remainder of
the line is interpreted. The following are the list of key letters understood.
- | any text
- Lines beginning with a vertical bar are treated as comments
and ignored by the program.
- add type gate source drain length width
- Add a new transistor of type to the network.
Currently, type may be:
- n-channel enhancement transistor.
- p-channel enhancement transistor.
- depletion transistor (for NMOS).
The names of the nodes to which the gate, source, and drain of the transistor
are connected are given by gate, source,
respectively. The length and width of the transistor are given by
respectively. The area
given, will use that number as the area for calculating the gate capacitance.
should be given in lambda units, area
should be in lambda ^2 units, these will internally be multiplied by the
LAMBDA factor from the configuration (.prm) file.
- delete type gate source drain length width
- Delete an existing transistor from the net. All the
parameters have the same meaning as for the add command.
- move type gate source drain length width
[area] g s d
- Move an existing transistor to a new location the net.
type, gate, source, drain, length, width, and area have the same
meaning as for the add command. g, s, and d are the
names of nodes to which the gate, source and drain should be connected. If
a particular terminal(s) is not to be re-connected, the name can be
specified using an "*". Any or all of g, s, and d
may be "*". For example, to move the gate of an n-channel
transistor from node old to new the following command would
m n old
src_node drn_node 4 2.2 new * *
- Note that the drain and source terminals, and
the g and s terminals are interchangeable; the simulator
will know if these are swapped. So the last example could also have been
m n old
drn_node src_node 4 2.2 new * *
- capacitance node value
- Change the capacitance of a node by value
picofarads. Value may be negative, thereby decreasing the node's
capacitance. Node is the node name.
- N node metal-area poly-area diff-area
- Change the capacitance of node using the area and
perimeter information of the metal, polysilicon, and diffusion layers. All
the parameters should be in lambda (or lambda ^2 for areas) units, they
will internally be converted to the appropriate capacitance as defined in
the configuration file. The values can be negative to decrease the
- M node M2A M2P MA MP PA PP DA DP PDA PDP
- Change the capacitance of node, using the following
- area of 2nd-level metal
- perimeter of 2nd-level metal
- area of 1st-level metal
- perimeter of 1st-level metal
- area of polysilicon
- perimeter of polysilicon
- area of n-diffusion
- perimeter of n-diffusion
- area of p-diffusion
- perimeter of p-diffusion
All perimeter values should be in lambda units, area values should be in lambda
^2 units. The perimeter measures are half of the actual total perimeter (i.e.,
they are the sum of the lengths of the top and one side). Again, the values
may be negative to decrease the capacitance of the node.
- threshold node low high
- Change the threhsold voltages of node. Low
and high should be in normalized voltage units (i.e. floating-point
numbers in the range 0.0 to 1.0).
- Delay node tplh tphl
- Change the delays for node to be tplh
nanoseconds for low-to-high transistions, and tphl ns. for
high-to-low transistions. These should be absolute numbers, not relative
- For all commands, only the first letter is significant, the
rest of the string will be ignored. They are only shown here for clarity.
This is an experimental interface for the incremental simulator and is very
likely to change in the future.
irsim(5) sim(5) presim(1)