A data processing apparatus includes a storage element and a clock controller. The storage element has storage partitions, including a first storage partition and a second storage partition. The clock controller controls clock driving of the first storage partition and the second storage partition. When a processing circuit is configured to operate in a first condition to process a first data sample with a first bit width, the clock controller enables clock driving of both of the first storage partition and the second storage partition. When the processing circuit is configured to operate in a second condition to process a second data sample with a second bit width, the clock controller enables clock driving of the first storage partition and disables clock driving of the second storage partition.