What is a PDB (parts database)?
A parts database is a (very simple) database which ties, or unites the symbol to the cell. It is the most central part of the device. It includes the symbol pin names and assigns them to the cell pin numbers. The PDB controls the swapping options. It includes the full part number and a description of the part. It also includes the value and cost as well as other properties such as a simulation model when available. It is the Device! The PDB allows for multiple symbols and cells to be referenced for each device. An example would be an AND gate and a NAND gate for symbols and a DIP package and an alternate package for cells. It is important to have a separate entry for each part distinguished by its (orderable) part number. This information will show up in the BOM (bill of material) list and will make ordering parts much easier if the information is correct. Cells are the Footprints! It is best that the people most familiar with the CAD system create cells. It s not that it s hard to do,
