A memory includes a determination circuit, a plurality of refresh counters, and a plurality of banks. The determination circuit receives a refresh command. The plurality of refresh counters are coupled to the determination circuit. Each refresh counter of the plurality of refresh counters corresponds to one bank of the plurality of banks. The determination circuit detects whether a first bank of the plurality of banks is enabled or a number counted by a first refresh counter of the plurality of refresh counters corresponding to the first bank is equal to a predetermined value. Then, the determination circuit optionally refreshes one bank of the plurality of banks according to a detection result. Thus, the memory still refreshes an idle bank according to a refresh command even if the plurality of banks are not all idle.