Large semiconductor memories have many bits that could fail, and each has a number of failure modes, so thorough testing can be quite time-consuming. The authors suggest that a small number of transistors be added to each memory chip so that testing can be conducted in parallel. They present algorithms for utilizing this extra hardware that will greatly speed up testing. These algorithms model the set of possible patterns of the bits that surround a given bit as a hypercube and express the tests as Eulerian or Hamiltonian paths through the hypercube. As I read the paper, I came to wonder whether the same extra hardware, or some variant of it, could provide a limited form of content-addressable memory (the authors do not explore this potential).

If you are concerned with testing memories, even without extra transistors, this paper is essential reading. You may also find it rewarding if you have an interest in combinatorial algorithms.