Design And Test of the 80386

A complex design effort, the 80386 was nevertheless one of the company's most successful projects. The work was completed in less time than scheduled and set an Intel record for tapeout to mask fabricator. The strategy incorporated both top-down and bottom-up design approaches. The top-down flow was external architectural definition, internal architecture, internal unit RTL (register transfer logic) and finally detailed logic. The bottom-up flow was detailed transistor and cell circuit design and layout, block (ALU, PLA, etc.) circuit design and layout, and finally global circuit design and layout. Testability also played an important part in the design's success. The 80386 combines two forms of designed-in test functions: built-in self-test and test hooks or functions explicitly designed in to aid testing.