A system includes a hard disk controller configured to, using only a single pin, transfer serial information from the hard disk controller. The serial information includes control data associated with control of both write operations and read operations. The serial information includes a first bit indicating a start of the control data, a predetermined number of bits of the control data following the first bit, and a second bit indicating an end of the predetermined number of bits of the control data. A read/write channel is configured to receive the serial information and perform the write operations and the read operations based on the serial information.