Provided by: magic_7.5.214-1_i386
sim - format of .sim files read by esim, crystal, etc.
The simulation tools crystal(1) and esim(1) accept a circuit
description in .sim format. There is a single .sim file for the entire
circuit, unlike Magic's ext(5) format in which there is a .ext file for
every cell in a hierarchical design.
A .sim 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.
| units: s tech: tech format: MIT|LBL|SU
If present, this must be the first line in the .sim file. It
identifies the technology of this circuit as tech and gives a
scale factor for units of linear dimension as s. All linear
dimensions appearing in the .sim file are multiplied by s to
give centimicrons. The format field signifies the sim variant.
MIT and SU are compatible and understood by all tools. LBL is
understood only by gemini(1).
type g s d l w x y g=gattrs s=sattrs d=dattrs
Defines a transistor of type type. Currently, type may be e or
d for NMOS, or p or n for CMOS. The name of the node to which
the gate, source, and drain of the transistor are connected are
given by g, s, and d respectively. The length and width of the
transistor are l and w. The next two tokens, x and y, are
optional. If present, they give the location of a point inside
the gate region of the transistor. The last three tokens are
the attribute lists for the transistor gate, source, and drain.
If no attributes are present for a particular terminal, the
corresponding attribute list may be absent (i.e, there may be no
g= field at all). The attribute lists gattrs, etc. are comma-
separated lists of labels. The label names should not include
any spaces, although some tools can accept label names with
spaces if they are enclosed in double quotes. In version 6.4.5
and later the default format produced by ext2sim is SU. In this
format the attribute of the gate starting with S_ is the
substrate node of the fet. The attributes of the gate, and
source and substrate starting with A_, P_ are the area and
perimeter (summed for that node only once) of the source and
drain respectively. This addition to the format is backwards
C n1 n2 cap
Defines a capacitor between nodes n1 and n2. The value of the
capacitor is cap femtofarads. NOTE: since many analysis tools
compute transistor gate capacitance themselves from the
transistor's area and perimeter, the capacitance between a node
and substrate (GND!) normally does not include the capacitance
from transistor gates connected to that node. If the .sim file
was produced by ext2sim(1), check the technology file that was
used to produce the original .ext files to see whether
transistor gate capacitance is included or excluded; see ``Magic
Maintainer's Manual #2: The Technology File'' for details.
R node res
Defines the lumped resistance of node node to be res ohms. This
construct is only interpreted by a few programs.
r node1 node2 res
Defines an explicit resistor between nodes node1 and node2 of
resistance res ohms. This construct is only interpreted by a
N node darea dperim parea pperim marea mperim
As an alternative to computed capacitances, some tools expect
the total perimeter and area of the polysilicon, diffusion, and
metal in each node to be reported in the .sim file. The N
construct associates diffusion area darea (in square
centimicrons) and diffusion perimeter dperim (in centimicrons)
with node node, polysilicon area parea and perimeter pperim, and
metal area marea and perimeter mperim. This construct is
technology dependent and obsolete.
A node attr
Associates attribute attr for node node. The string attr should
contain no blanks.
= node1 node2
Each node in a .sim file is named implicitly by having it appear
in a transistor definition. All node names appearing in a .sim
file are assumed to be distinct. Some tools, such as esim(1),
recognize aliases for node names. The = construct allows the
name node2 to be defined as an alias for the name node1.
Aliases defined by means of this construct may not appear
anywhere else in the .sim file.
crystal(1), esim(1), ext2sim(1), sim2spice(1), ext(5)