eldo_user

Eldo Netlist Setup
Expressions
Specifying the Simulation Time in Expressions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 119
Conditional Evaluation of Expressions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 119
Specifying the Simulation Time in Expressions
The current simulation time can be specified inside expressions using the TIME keyword.
TIME is a variable returned by the simulator which gives the value of the current simulation
time and may be used in subsequent calculations. The TIME variable may be used in the
formulation of time-dependent expressions.
The TIME variable may be used in conjunction with VALUE={EXPR} in resistors, capacitors,
inductors, and E and G sources to specify devices/sources whose values vary with time.
g1 1 0 value={TIME * 1u}
r1 1 0 1
.tran 1 10
.print tran v(1)
.end
This specifies a voltage controlled current source between nodes 1 and 0. The current through
g1 from node 1 to node 2 is equal to the current simulation time (TIME) multiplied by 1×10 −6 .
Related Topics
Expressions
Conditional Evaluation of Expressions
Conditional Evaluation of Expressions
Parameters or source values can be evaluated in expressions containing conditional statements.
Syntax
VALIF(CONDITION,expression1,expression2)
EVAL(CONDITION?expression1:expression2)
If CONDITION is TRUE, then VALIF (or EVAL) returns expression1 else it returns
expression2. The keyword VALIF (or EVAL) can be used in any expression. The VALIF
operator also accepts strings in .PARAM statements. This is useful for selecting models
according to parameter values.
Examples
.param p1 = 1.0
.param p2 = 2.0
.param p3 = valif(p1>p2,p1+1.5,p2+1.5)
Here, P3 will be assigned the value 3.5.
Eldo® User's Manual, 15.3 119