NETCHANGE(5) IRSIM User's Manual NETCHANGE(5)NAMEnetchange - format of netchange files read by irsim.
DESCRIPTION
A netchange 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 [area]
Add a new transistor of type to the network. Currently, type
may be:
n n-channel enhancement transistor.
p p-channel enhancement transistor.
d 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, and
drain respectively. The length and width of the transistor are
given by length and width respectively. The area parameter, if
given, will use that number as the area for calculating the gate
capacitance. Length and width should be given in lambda units,
area should be in lambda^2 units, these will internally be mul‐
tiplied by the LAMBDA factor from the configuration (.prm) file.
delete type gate source drain length width [area]
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 mean‐
ing 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 be used:
m n old src_node drn_node 4 2.2 new * *
Note that the drain and source terminals, and the g and s termi‐
nals are interchangeable; the simulator will know if these are
swapped. So the last example could also have been written:
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 diff-perimeter
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 capacitance.
M node M2A M2P MA MP PA PP DA DP PDA PDP
Change the capacitance of node, using the following geometrical
information:
M2A area of 2nd-level metal
M2P perimeter of 2nd-level metal
MA area of 1st-level metal
MP perimeter of 1st-level metal
PA area of polysilicon
PP perimeter of polysilicon
DA area of n-diffusion
DP perimeter of n-diffusion
PDA area of p-diffusion
PDP 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 neg‐
ative 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 increments/der‐
crements.
NOTE: For all commands, only the first letter is significant, the rest
of the string will be ignored. They are only shown here for
clarity.
BUGS
This is an experimental interface for the incremental simulator and is
very likely to change in the future.
SEE ALSOirsim(5)sim(5)presim(1)3rd Berkeley DistributionNETCHANGE(5)
