Patent ID: 7280302

Claim:
A disk drive for connecting to a host, the host comprising loopback circuitry operable to loop a pattern received from the disk drive back to the disk drive, the disk drive comprising: (a) a disk; (b) a head actuated over the disk; (c) interface circuitry for interfacing with the host, the interface circuitry comprising: a transmitter driver operable to transmit transmission signals at a transmission amplitude; and a receiver driver operable to receive reception signals; and (d) control circuitry operable to calibrate the transmission amplitude by: configuring the transmitter driver to transmit at an initial transmission amplitude; transmitting a calibration pattern to the host through the transmitter driver; monitoring the reception signals received by the receiver driver to detect a loopback pattern representing a loopback of the calibration pattern; processing the loopback pattern to detect an error; and adjusting the transmission amplitude in response to the error.