Traditional metrics used to compare hardware designs include area, performance, and power. However, these metrics do not form a complete evaluation of reconfigurable hardware. For these designs, flexibility is also a key issue, since it is the flexibility of reconfigurable hardware that allows it to implement a variety of circuits. Despite its importance, there is not yet an established method to measure flexibility. This paper explores the flexibility testing issue for domain-specific reconfigurable architectures. We discuss the concept of flexibility as it pertains to domain-specific architectures, and propose a flexibility testing technique involving synthetic circuit generation. This technique is then used to compare three different domain-specific architecture generation algorithms, demonstrating that the testing can in fact differentiate between architectures of differing levels of flexibility. Categories and Subject Descriptors B.6 [Logic Design]; B.6.3 [Design Aids]: Automatic...