Transparency-based hierarchical test generation for modular RTL designs

We discuss a novel hierarchical test generation methodology for RTL designs, based on the concept of modular transparency. We introduce the channel notion, a powerful mechanism that captures modular transparency in terms of bijection functions defined on variable bitwidth signal entities. Through a recursive search algorithm, transparency channels are further combined into reachability paths suitable for translating local test vectors for each module into global design test. A divide and conquer hierarchical test generation methodology is described, resulting in significant test generation time speed-up and comparable fault coverage and vector count to complete circuit gate-level ATPG.