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- NETCHANGE(5)
-
- NAME
- netchange - 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 inter-
- preted. The following are the list of key letters under-
- stood.
-
- | any text
- Lines beginning with a vertical bar are treated as com-
- ments 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 capa-
- citance. Length and width 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 [area]
- Delete an existing transistor from the net. All the
- parameters have the same meaning as for the add com-
- mand.
-
- 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, 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 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 terminals 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 per-
- imeter information of the metal, polysilicon, and dif-
- fusion 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 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 increments/dercrements.
-
- NOTE: For all commands, only the first letter is signifi-
- cant, the rest of the string will be ignored. They
- are only shown here for clarity.
-
-
- BUGS
- This is an experimental interface for the incremental simu-
- lator and is very likely to change in the future.
-
-
- SEE ALSO
- irsim(5) sim(5) presim(1)
-
-