 
 
 
 
 
 
 
  
 Next: Functions
 Up: Behavioral modeling
 Previous: Behavioral modeling
     Contents 
Subsections
GnuCap behavioral modeling conditionals are an extension of the ``AC''
and ``DC'' Spice source parameters.  
The extensions ...
- There are more choices, including an ``else''.
 
- They apply to all elements (primitive components).
 
- Each section can contain functions and options.
 
The following are available:
- AC
- AC analysis only.
- DC
- DC (steady state) value.
- OP
- OP analysis.
- TRAN
- Transient analysis.
- FOUR
- Fourier analysis only.
- ELSE
- Anything not listed.
- ALL
- Anything not listed.
 
A value or function with no conditional keyword is equivalent to ALL.  For SPICE compatibility, use only DC, AC, or nothing.
They are interpreted like a ``switch'' statement.  In case of a
conflict, the last one applies.  A set of precedence rules applies
when some keys are missing.  It is SPICE compatible, to the extent the
features overlap.
- OP analysis
- OP, DC, ALL, TRAN, 0
- DC analysis
- DC, ALL, OP, TRAN, 0
- Transient analysis
- TRAN, ALL, DC, OP, 0
- Fourier analysis
- FOUR, TRAN, ALL, DC, OP, 0
- AC analysis, fixed sources
- AC, 0
- AC analysis, other elements
- AC, ALL, 0
 
- V12 1 0 AC 1 DC 3
- This voltage source has a value of 1
for AC analysis, 3 for DC.  OP, Transient, and Fourier inherit the DC value.
 
- R44 2 3 OP 1 ELSE 1g
- This resistor has a value of 1 ohm
for the ``OP'' analysis, 1 gig-ohm for anything else.  This might be
useful as the feedback resistor on an op-amp.  Set it to 1 ohm to set
the operating point, then 1 gig to measure its open loop
characteristics, hiding the fact that the op-amp would probably
saturate if it was really left open loop.
 
 
 
 
 
 
 
 
  
 Next: Functions
 Up: Behavioral modeling
 Previous: Behavioral modeling
     Contents 
Al Davis
2001-10-28