= Equals Illegal Illegal Optional in .PARAM statements Delimiter < > Less/more than Legal anywhere Included only Included only n/a ? Question mark Legal anywhere Included only Included only Wildcard character / Forward slash Legal anywhere Included only Illegal n/a { } Curly braces included only, converts to [ ] Included only Included only Engine shall auto-convert to square brackets ( [ ] ) [ ] Square brackets Included only Included only Included only n/a \\ Double backslash Included only Illegal Illegal Continuation character sequence | Pipe Legal anywhere Included only Included only n/a , Comma Illegal Illegal Illegal Delimiter . Period Illegal Illegal Illegal Used only as a special statement identifier (i.e., .PARAM) : Colon Included only Included only Included only Delimiter for element attributes
R Resistor R10 21 10 1000 S S-parameter element S1 nd1 nd2 MNAME=s_model2 T Transmission line Txxx in 0 out 0 Zo=50 + TD=30n V DC voltage source V1 8 0 DC=0 W Transmission line W1 in1 0 out1 0 N=1 L=1 + TABLEMODEL=my_table X Subcircuit instance X1 2 4 17 31 MULTI WN=100 + LN=5 Numbers Numbers may be entered as integer, floating point, floating point with an integer exponent, or integer or floating point with one of the scale factors listed below. Table 6: Scale Factors Scale Factor IEEE Standard Prefix IEEE Standard Symbol Multiplying Factor T tera T 1e+12 G giga G 1e+9 MEG mega M 1e+6 K kilo k 1e+3 MIL n/a mil 25.4e-6
M milli m 1e-3 U micro 1e-6 N nano n 1e-9 P pico p 1e-12 F femto f 1e-15 A atto a 1e-18 Scale factor A is not a scale factor in a character string that contains amps. For example, IBIS-ISS-compliant tools shall interpret the string "20amps" as 20 amperes of current, not as 20e-18mps. Numbers may use exponential format or engineering key letter format, but not both (1e-12 or 1p, but not 1e-6u). To designate exponents, use D or E. Trailing alphabetic characters are interpreted as units comments (for example, 1kV is interpreted as 1k, while 1w is interpreted as 1). Units comments are not checked. Parameters and Expressions Parameter names shall begin with an alphabetic character. Subsequent characters in the parameter name shall be either alphanumeric characters or special characters as defined in If multiple definitions are given for the same parameter, IBIS-ISS uses the last parameter definition even if that definition occurs later in the input than a reference to the parameter. A parameter shall be defined before that parameter is used in a definition for another parameter.
The RLGCMODEL and TABLEMODEL arguments associate a W-element definition with a .MODEL using either Format 1 or Format 2, respectively. A W-element shall use either RLGCMODEL or TABLEMODEL, but not both. In both formats, the characteristics of the W-element are expressed in per unit length matrices: Ro (DC resistance), L, G, C, Rs (skin effect), and Gd (dielectric loss). Format 1: RLGC Model The RLGC .MODEL format supports frequency-independent RLGC matrices per unit length. The format also supports frequency-dependent R and G data, and lossless (LC) lines. It does not support RC lines. Because RLGC matrices are symmetrical, the RLGC model specifies only the lower triangular parts of the matrices. The syntax of the RLGC model for the W-element is: .MODEL name W MODELTYPE=RLGC N=val + Lo=matrix_entries + Co=matrix_entries [Ro=matrix_entries] [Go=matrix_entries] + [Rs=matrix_entries] [Gd=matrix_entries] [Rognd=val] + [Rsgnd=val] [Lgnd=val] Table : W-element RLGC Model Arguments Argument Description Units N=val Sets positive non-zero integer val as the number of signal conductors (excluding the reference conductor). Lo=matrix_entries DC inductance matrix, per unit length. H/m Co=matrix_entries DC capacitance matrix, per unit length. F/m Ro=matrix_entries DC resistance matrix, per unit length. Ω/m Go=matrix_entries DC shunt conductance matrix, per unit length. S/m