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4.1.4.2 Add attributes

For more information on the attributes presented here, please see the Master attribute list.

  1. A device=DEVICENAME attribute should be placed somewhere in the symbol and made invisible. Typically the devicename is in all caps (capital letters). This attribute should not be used as a label. Use a separate text object for the label. If the object is a graphic then device= should be set to none (device=none).
  2. A graphical=1 attribute should exist somewhere in a symbol which is purely graphical (such as a title block or decon symbol). Symbols which have this attribute have no electrical or circuit significance. Don’t forget to set device=none per the previous requirement.
  3. A description=TEXT attribute should exist somewhere in the symbol. The TEXT value should provide a one line description of the symbol.
  4. A footprint=PACKAGENAME attribute should exist somewhere in the symbol which might be used with a pcb netlister. PACKAGENAME is a pcb footprint or package type like DIP14 or DIP40. Please see the footprint naming conventions page for further detail. If you are using gEDA / PCB, also see the PCB documentation and gnetlist/docs/README.pcb for more info on this attribute and how it is used.
  5. A refdes=U? attribute should be placed inside all non-graphical symbols. Make only the value visible and it will be promoted (attached to the outside of the symbol, so it can be edited) when the symbol is placed in a schematic.
  6. The label= and name= attributes should not exist anywhere in the symbol. They are obsolete.
  7. The netname= attribute should not be attached anywhere in the symbol. It is only used in schematics.

4.1.4.3 Slotting

  1. If a component has multiple slots in a package (such as a 7400 (NAND) which has 4 NANDs per package) then you need a numslots=# attribute. The # is the number of slots the device has. numslots= should be exist somewhere in the symbol and made invisible. Additional slot related required attributes are described below.
  2. If a component has multiple slots in a physical package then you also need to include a slotdef=#:#,#,#... for every slot. The first # corresponds to the slot number. If a device has 4 slots then there should be slotdef=1:..., slotdef=2:..., slotdef=3:..., and slotdef=4:..., attributes existing somewhere in the symbol and made invisible. The subsequent # have a one-to-one correspondence to pinseq=# attributes and specify what corresponding pinnumber=# should be when that slot is set. See the attached 7400-1.sym as an example of how this should all work.
  3. It is recommended that all symbols which have slots have a slot=1 attribute inside the symbol.

4.1.5 Checking a Symbol

Running gsymcheck will check that all of these requirements are met. gsymcheck will output fatal errors which are quite serious and must be corrected. gsymcheck will also output warnings on things which should be fixed but are not fatal.

4.1.6 Style

This section describes the style which is used in the standard gEDA/gaf symbol library.

4.1.6.1 Text

4.1.6.2 Attributes

4.1.6.3 Graphics

4.1.6.4 Pins

4.1.6.5 Electrical

4.1.7 Hints and Tips

This section describes some hints and tips which will make your symbol creation experience easier.


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