MAZeT devises a redesign strategy for ASICs

As concerns for the redesign of digital ASICs have risen, various methods have become available, including mask-programmable and standard-cell technology or replacement with a programmable logic module. A mixed-signal ASIC contains digital modules as well as an analogue component of variable size. The redesign effort is reduced by using analogue or digital IPs, a database that is as complete as possible, comprehensive and detailed documentation of the ASIC, as well as a testing environment. When implementing a concrete redesign order for a mixed-signal ASIC, MAZeT eliminated the weaknesses of the original ASIC. For example, the previous 0.6µm CMOS technology was replaced by 0.35µm CMOS technology, which will be available in the long term. Despite the redesign, the entire pin assignment was retained, enabling the continued use of existing PCBs.

Successful ASIC redesign is subject to several conditions. The more of these are met, the lower the design risk, development time and redesign costs. The top priority is to provide a technical description including a requirements specification, circuit plan, high-level language description, netlist and datasheet in order to ensure functional compatibility. The testing vectors and environment are essential for delivering the proof of functionality needed for series production. The dynamic behaviour is also important, as the logic elements of a new semiconductor technology often exhibit different delay times and the analogue transistors display a different electrical behaviour. Other prerequisites include the testing programme for the circuit tester, precise documentation of the ASIC’s electrical functions, the electrical characterisation of the input/output behaviour, the supply voltage concept, the ESD and EMC concept, and the GDS2 data set.

“ASICs offer significant benefits compared to standard ICs,” said Dr. Fred Grunert, Managing Director, MAZeT. “An electronics concept geared towards a specific application contains precisely the required function range, which consequently reduces costs and results in a compact solution. The electrical properties are also improved. On the downside, parts are only available for approximately six to eight years, and stock-keeping is limited to no more than two years. To help companies struggling with these issues, MAZeT developed the redesign solution. A redesign increases availability and also makes it possible to further optimise the ASIC.”