1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
|
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 transitions, and tphl ns. for high-to-low
transitions. 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)
|
