A ULA is More than Silicon

The authors report a LSI design system using ULAs (a ULA is an LSI chip that contains a regular array of identical cells of semiconductors and resistors). The design is elegant and has greater DA support than the printed circuit boards it is replacing. The time taken from the chip specification to the pattern generator tape is about two weeks. If the chip logic simulation is extended to cover many chips plus support logic then this period of time is increased. To reduce the time from the pattern generator tape to the samples ICL has purchased an ElectroMask mask maker. The normal turnround time from pattern generator tape to working samples is expected to be four weeks, with an express route which takes 1 week on a limited number of parts. The authors believe that both simulation to check design integrity, and fast LSI design turnround times are essential to manage the complexity. This design system described meets this objective economically.