Saturating counters: application and design alternatives

We define a new class of parallel counters, saturating counters, which provide the exact count of the inputs that are 1 only if this count is below a given threshold. Such counters are useful in, for example, a self-test and repair unit for embedded memories in a system-on-a-chip. We describe this application and present several alternatives for the design of the saturating counter. We then compare the delay and area of the proposed design alternatives.