1NETCHANGE(5) IRSIM User's Manual NETCHANGE(5)
2
6 netchange - format of netchange files read by irsim.
7
10 A netchange file consists of a series of lines, each of which begins
11 with a key letter. The key letter beginning a line determines how the
12 remainder of the line is interpreted. The following are the list of
13 key letters understood.
14 | any text
16 Lines beginning with a vertical bar are treated as comments and
17 ignored by the program.
18 add type gate source drain length width [area]
20 Add a new transistor of type to the network. Currently, type
21 may be:
22 n n-channel enhancement transistor.
23 p p-channel enhancement transistor.
24 d depletion transistor (for NMOS).
25 The names of the nodes to which the gate, source, and drain of
27 the transistor are connected are given by gate, source, and
28 drain respectively. The length and width of the transistor are
29 given by length and width respectively. The area parameter, if
30 given, will use that number as the area for calculating the gate
31 capacitance. Length and width should be given in lambda units,
32 area should be in lambda^2 units, these will internally be mul‐
33 tiplied by the LAMBDA factor from the configuration (.prm) file.
34 delete type gate source drain length width [area]
36 Delete an existing transistor from the net. All the parameters
37 have the same meaning as for the add command.
38 move type gate source drain length width [area] g s d
40 Move an existing transistor to a new location the net. type,
41 gate, source, drain, length, width, and area have the same mean‐
42 ing as for the add command. g, s, and d are the names of nodes
43 to which the gate, source and drain should be connected. If a
44 particular terminal(s) is not to be re-connected, the name can
45 be specified using an "*". Any or all of g, s, and d may be
46 "*". For example, to move the gate of an n-channel transistor
47 from node old to new the following command would be used:
48 m n old src_node drn_node 4 2.2 new * *
50 Note that the drain and source terminals, and the g and s termi‐
52 nals are interchangeable; the simulator will know if these are
53 swapped. So the last example could also have been written:
54 m n old drn_node src_node 4 2.2 new * *
56 capacitance node value
58 Change the capacitance of a node by value picofarads. Value may
59 be negative, thereby decreasing the node's capacitance. Node is
60 the node name.
61 N node metal-area poly-area diff-area diff-perimeter
63 Change the capacitance of node using the area and perimeter
64 information of the metal, polysilicon, and diffusion layers.
65 All the parameters should be in lambda (or lambda^2 for areas)
66 units, they will internally be converted to the appropriate
67 capacitance as defined in the configuration file. The values
68 can be negative to decrease the capacitance.
69 M node M2A M2P MA MP PA PP DA DP PDA PDP
71 Change the capacitance of node, using the following geometrical
72 information:
73 M2A area of 2nd-level metal
75 M2P perimeter of 2nd-level metal
76 MA area of 1st-level metal
77 MP perimeter of 1st-level metal
78 PA area of polysilicon
79 PP perimeter of polysilicon
80 DA area of n-diffusion
81 DP perimeter of n-diffusion
82 PDA area of p-diffusion
83 PDP perimeter of p-diffusion
84 All perimeter values should be in lambda units, area values
86 should be in lambda^2 units. The perimeter measures are half of
87 the actual total perimeter (i.e., they are the sum of the
88 lengths of the top and one side). Again, the values may be neg‐
89 ative to decrease the capacitance of the node.
90 threshold node low high
92 Change the threhsold voltages of node. Low and high should be
93 in normalized voltage units (i.e. floating-point numbers in the
94 range 0.0 to 1.0).
95 Delay node tplh tphl
97 Change the delays for node to be tplh nanoseconds for low-to-
98 high transistions, and tphl ns. for high-to-low transistions.
99 These should be absolute numbers, not relative increments/der‐
100 crements.
101 NOTE: For all commands, only the first letter is significant, the rest
103 of the string will be ignored. They are only shown here for
104 clarity.
105
108 This is an experimental interface for the incremental simulator and is
109 very likely to change in the future.
110
113 irsim(5) sim(5) presim(1)
1143rd Berkeley Distribution NETCHANGE(5)