A memory macro includes a first memory cell array, a first tracking circuit, a first and a second transistor. The first tracking circuit includes a first set of memory cells configured as a first set of loading cells responsive to a first control signal, a second set of memory cells configured as a first set of pull-down cells responsive to a second control signal, and a first tracking bit line extending over the first tracking circuit. The second control signal is inverted from the first control signal. At least the first set of pull-down cells or the first set of loading cells is configured to track a memory cell of the first memory cell array. The first and second transistor are coupled to the first tracking bit line, and are configured to charge the first tracking bit line to a pre-charge voltage level responsive to a third control signal.