A high-packing density module generator for bipolar analog LSIs

Efficient placement and routing algorithms are presented for the modules of a bipolar analog LSI. In the layout of an analog module, a grid-free technique is required to minimize the module area and geometric constraint observance is necessary for the circuit performance optimization. The placement algorithm determines cell positions observing the geometric constraints by vertex-grouping of the constraint graph representing the relative device positions in the input circuit diagram. The routing algorithm, based on the characteristic fine-grid maze router, allows grid-free routing and variable width routings observing the geometric constraints by dynamically generating wiring prohibition. These algorithms are applied to the design of the analog modules. Automatically designed modules are compact and the performance requirements are met.<>