Hierarchical symbolic design methodology for large-scale datapaths

Abstract

A hierarchical symbolic layout methodology for designing large-scale datapaths is proposed. The methodology constructs a datapath hierarchically by taking note of the bit-slice regular structure. It gives a globally optimized layout with a rapid optimizing loop. This approach has reduced design effort to 1/10 compared with conventional handcraft design (maintaining equivalent layout quality) for a datapath which includes 21 K transistors. Macrocells without bit-sliced structure are also considered to be easily embedded into the final datapath layout. Moreover, as a design entry, an LT-diagram entry is allowed for a designer. The diagram is a special logic diagram which includes topological information for gates and wirings. A stick-diagram is automatically synthesized from the LT-diagram and mask layout is generated through compaction. >