USING TOP-DOWN CAD TOOLS FOR MIXED ANALOG DIGITAL ASICS - A PRACTICALDESIGN CASE/

A mixed analog/digital ASIC from a real satellite application (a radia tion detector front-end) has been designed, simulated and processed ac cording to a hierarchical top-down design methodology, CAD tools (comm ercial and academic) have been used as much as possible. The top-down methodology is discussed and illustrated by going through the differen t steps of the ASIC design, At each level the different choices and tr adeoffs are briefly discussed and practical difficulties of top-down d esign are pointed out, One of the most important problems in top-down mixed-signal ASIC design-modeling and verification-is highlighted and discussed in detail.