A memory controller and an associated controlling method are provided. The memory controller is connected to a memory module, and includes a FIFO buffer for receiving valid data outputted from the memory module, a write pointer for indicating written data stored in the FIFO buffer, and a read pointer for indicating read data stored in the FIFO buffer. According to the controlling method, during a CAS latency of the memory module after a read command is generated, the value of the write pointer is controlled to have the same value as that of the read pointer.