A disclosed apparatus for accomplishing such a task may include (1) a circuit board incorporated into a module designed for insertion into slots of computing devices, (2) at least one conductive contact disposed on the circuit board, (3) a counter circuit disposed on the circuit board and communicatively coupled to the conductive contact, wherein the counter circuit comprises (A) a signal-change detector that detects signal changes as the module is inserted into one of the slots of the computing devices and (B) a counter device that maintains a dynamic count indicative of a number of times that the module has been inserted into one of the slots of the computing devices based at least in part on the signal changes, (4) a battery electrically coupled to the counter circuit, wherein the battery powers the counter device prior to the insertion. Various other apparatuses, systems, and methods are also disclosed.

An apparatus has a collection of ring oscillators. An instruction register block is configured to sequentially address and activate each ring oscillator in the collection of ring oscillators. A multiplexer with input lines is connected to each ring oscillator in the collection of ring oscillators and an output line. A pulse counter is connected to the output line of the multiplexer to count the number of oscillations of a selected ring oscillator within a selected time period to form a multiple bit frequency count output signal. A data shift register receives the multiple bit frequency count output signal and produces a serial frequency count output signal.

An apparatus has a collection of ring oscillators. An instruction register block is configured to sequentially address and activate each ring oscillator in the collection of ring oscillators. A multiplexer with input lines is connected to each ring oscillator in the collection of ring oscillators and an output line. A pulse counter is connected to the output line of the multiplexer to count the number of oscillations of a selected ring oscillator within a selected time period to form a multiple bit frequency count output signal. A data shift register receives the multiple bit frequency count output signal and produces a serial frequency count output signal.

Solutions for testing a digital hardware counter circuit are disclosed. In an example, a software module tests a plurality of most significant bits. The count value is set to a binary value. For a down counter, the bit of the binary value at the current bit position is set to high and lower bits are set to low. For an up counter, the bit of the binary value at the current bit position is set to low and lower bits are set to high. Next, the software module enables the counter. The counter varies the count value. After a time-period, the software module disables the counter and determines whether one or more bits of the count value have an expected value(s). When at least one of the one or more bits of the count value does not have the respective expected value, the software module signals a malfunction.