Headings:

4 - Schematic Implementation

4.1 - Linking the Schematic to the Printed Circuit

4.2 - Procedure for Creating the Printed Circuit

4.3 - Procedure for Updating the Printed Circuit

Schematic Implementation

Linking the Schematic to the Printed Circuit

The schematic is linked to PCBNEW by means of the Netlist file, which is normally generated by the schematic program used.

Note: PCBNEW accepts Netlist files with the EESchema or ORCAD PCB 2 formats.

The Netlist file initially generated is usually incomplete as there has been no assignment of the modules that correspond to the various components used in the schematic. Consequently an intermediate stage is necessary, the generation of the file of association components/modules.

CVPCB is used to create this file which is named * .CMP.

CVPCB also updates the Netlist file using this information.

PCBNEW reads the modified Netlist file * .NET and, if it exists, the file * .CMP.

In the event of a module being changed directly in PCBNEW the * .CMP file is automatically updated so avoiding the requirement to run CVPCB again.

Procedure for Creating the Printed Circuit

After having created the required schematic:

Generate the netlist using Eeschema.

Assign each components in the Netlist produced by Eeschema to the corresponding module used on the printed circuit using CVPCB.

Launch PCBNEW and read the modified Netlist (this will also read the file with the module selections).

PCBNEW will then load automatically all the modules.

The modules can now be placed manually or automatically on the board and and the tracks routed.

Procedure for Updating the Printed Circuit

If the schematic is modified, the following steps must be repeated:

Generate a new netlist using Eeschema.

If the changes to the schematic involve new components, the corresponding modules must be assigned using CVPCB.

Launch PCBNEW and re-read the modified Netlist (this will also re-read the file with the module selections).

PCBNEW will then load automatically any new modules, add the new connections and remove redundant connections.

PCBNEW: Schematic Implementation

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Keith Cockburn

2005-06-14T14:24:31

Keith Cockburn