US Patent 11521669 Semiconductor device having cam that stores address signals

An apparatus may include multiple address registers each storing an address signal and multiple counter circuits each storing a count value corresponding to an associated one of the address registers. The apparatus may include a first circuit cyclically selecting one of the address registers in response to a first signal, a second circuit selecting one of the address registers based on the count value of each of the counter circuits, and a third circuit activating a second signal when the first and second circuits select the same one of the address registers.