Backannotation is the process of updating schematics to reflect
changes made in the layout. This process is used, for example, when
the reference designators have been renumbered on the layout, when
pins have been swapped (e.g. on an AND gate), or slots have been
swapped (e.g. on a multi-gate package). This section describes how to
backannotate changes in a Pads PowerPCB layout to a gEDA schematic.
The Pads PowerPCB tool supports three types of schematic
backannotation:
- Reference designator changes. This is often times used at the
end of a layout to give components which are geographically close a
set of reference designators which are numerically close.
- Slot swapping. This is commonly found in digital designs where
there may be multiple identical gates in a single package. For
example, you may wish to swap which slot is used in a hex inverter.
- Pin swapping. During layout, the designer may wish to swap
equivalent pins on a chip. For example, the two inputs on a NAND
gate.
Currently only reference designator changes are automatically
processed by the Pads to gschem backannotation tool. The slot and pin
swapping changes are provided in a report which the schematic designer
must use to manually correct the schematic.
Subsections
Ales Hvezda
2005-08-20