4 gSchem Symbols

Anonymous edited this page 2021-07-14 17:37:22 +05:30

Table of Contents

• Procedure
• Hierarchical Symbols
• Also see:

Procedure

1. Draw the graphical part of the symbol (lines, boxes, delineation of internal connections)
2. Add pins (keyboard shortcut: ap) and fill in the attributes 'pinlabel','pinnumber','pinseq','pintype'. Normally, the first two attributes are kept visible while the other two are kept invisible. Use the pin name mentioned in the device datasheet as your 'pinlabel'. 'pinnumber' and 'pinseq' have the same value unless you are using slotting. 'pintype' should be one of the ten values mentioned in the gEDA Master Attribute Document and should be in lower case.
3. Add at least the following symbol attributes to the symbol: 'refdes', 'device', 'value', 'description', 'author', 'numslots' and 'footprint'
4. Make all attributes invisible (keyboard shortcut 'en') and translate the symbol to the origin using the keyboard shortcut 'et'. This ensures that the symbol appears at the right place when invoked.
5. Run gsymcheck on the symbol file to ensure it is alright

Hierarchical Symbols

These are symbols which represent underlying schematics (or netlists). There are some additional requirements in this case:

1. Source= attribute pointing to source schematic
2. model-name= attribute pointing to model name or subcircuit name with parameters
3. file= pointing to relative path of the sub-circuit prototype (SPICE subckt file)

Also see:

1. Some guidelines on the gEDA library page: on http://www.gedasymbols.org/csv.html
2. See the gEDA Master Attribute Document for the meanings of the attributes.
3. Automated tool for converting schematic to symbol: geda_sch2sym