Verification of a Modern Processor

Over the past four decades, microprocessors have come to be a vital and inseparable part of the modern world, becoming the digital brain of numerous electronic devices and gadgets that make today’s lifestyle possible. Processors are capable of performing computation at astonishingly high speeds and are extremely integrated, occupying only a few square centimeters of silicon die. However, this computational power comes at a price: the task of verifying a modern microprocessor and guaranteeing the correctness of its operation is increasingly challenging, even for most established processor vendors. To deliver always higher performance to end-users, processor manufacturers are forced to design progressively more complex circuits and employ immense verification teams to eliminate critical design bugs in a timely manner. Unfortunately, too often size doesn’t seem to matter in verification, as schedules continue to slip, and microprocessors find their way to the marketplace with design errors. In this chapter we overview the life-cycle of a microprocessors, discuss the challenges of verifying these devices, and show examples of hardware errors that have escaped into production silicon because of insufficient validation an d their impact.