ASICS. Can your designs be tested?

With the combination of surface-mount inter-connection technology and the ever increasing integrated circuit complexity of ASICs the problems of testing VLSI devices and PCBs must not be ignored. It has been said that 90% of the cost of digital devices could be due to testing. With a reduction of testing costs one will have a great advantages over the other manufacturers. There is no easy answer but it is always possible to design untestable circuits. A designer has to appreciate that he is responsible for the testing costs as well as the design costs. When a design is produced that can readily be tested then there is a much better chance that this product will be reliable and therefore easier to manufacture