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Automatic creation of symbols from schematics

Let's try to generate a symbol from a schematic.

First, pop up the symbol menu and choose 'gen autom. symbol'. If your schematic contains less than two ports ( SPICECAD version < 1.7.4 : named pins ) , you will receive an error message.

If your schematic seems to be correct, a dialog box (see picture 16.1) will pop up.


  
Figure 16.1: Automatic symbol generation dialog
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\includegraphics{gensymbol.ps}
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  Here, you can decide where to place contacts (left, right, upper, lower pins) and what the symbol should look like: like a box or like an opamp. If you choose the opamp, there must not be more than two contacts at the right side of the opamp. If you want to give local properties to the symbols, you can add them in the last line.

The creation of the symbol works very fast, so you don't have to wait for some actions after having pushed the creation button.

Afterwards, you should check the look of the new symbol and correct it wherever you like.

The next section describes how to create symbols semi-automatically. Do to this, SPICECAD searches for names pins and ports and displays them in a dialog box (see pictures 16.1 and 16.2). Afterwards, you can decide whether you want all pins and ports to appear at the symbol, or wheter do want to select a sub-set only. It is your decision. Of course, connections can be made only when having contacts inside the symbols and pins and ports inside the associated schematic.

  What is not allowed on deep hierarchy levels are property, option and analysis boxes. Erase them if you decide a top level schematic to become a symbol. Otherwise, you will get error messages during netlisting.


next up previous contents
Next: Automatic creation of symbols Up: Automatic creation of symbols Previous: Automatic creation of symbols
Martin Maschmann
1999-10-10