Targeting Internal-State Scenarios in an Uncertain World

The challenges inherent in verifying today's complex designs are widely understood. Just identifying and exercising all the operating modes of one of today's complex designs can be challenging. Creating tests that will exercise all these input cases is, likewise, challenging and labor-intensive. Using directed-test methodology, it is extremely challenging to create sufficiently-comprehensive tests to ensure design quality, due to the amount of engineering effort needed to design, implement, and manage the test suite. Random test methodology helps to address the productivity and management challenges, since automation is leveraged more efficiently. However, ensuring that all critical cases are hit with random testing is difficult, due to the inherent redundancy of randomly-generated stimulus.