Abstract: A disk drive including a method for determining an amplitude for signal transmission over an interconnect is disclosed. The drive includes a processor that is coupled to a signal measurement circuit and is under the control of a program in conjunction with the signal measurement circuit to transmit a first signal to the host over a transmission medium at a first transmission frequency according to a first speed negotiation process, receive a second signal from the host at the first transmission frequency, determine a first voltage amplitude of the second signal, transmit a third signal to the host at a second transmission frequency according to a second speed negotiation process, receive a fourth signal from the host at the second transmission frequency, determine a second voltage amplitude of the fourth signal, and determine an approximate voltage loss in response to the first and second voltage amplitudes.

Abstract: A method for determining an amplitude for signal transmission over an interconnect is disclosed. The method includes transmitting a first signal to a host over a transmission medium at a first transmission frequency according to a first speed negotiation process and receiving a second signal from the host at the first transmission frequency. The method also includes measuring a first voltage amplitude of the second signal and transmitting a third signal to the host at a second transmission frequency according to a second speed negotiation process. The method further includes receiving a fourth signal from the host at the second transmission frequency, measuring a second voltage amplitude of the fourth signal, and determining an approximate voltage loss in response to the first and second voltage amplitudes.

Abstract: A disk drive including a disk, a signal measurement circuit to measure amplitudes of signals received from the host, and a processor for controlling operations in the disk drive. The processor under the control of a program in conjunction with the signal measurement circuit: measures an amplitude of a signal from a host during a first speed negotiation process and determines if the amplitude of the signal from the host is above a pre-determined amplitude for the disk drive. If so, the processor commands the disk drive to transmit the signals to the host at the measured amplitude of the first speed negotiation process. However, if the amplitude is below the pre-determined amplitude for the disk drive, a second speed negotiation process is forced using a low frequency signal from the host and calculations are performed to determine appropriate transmit amplitudes for the interconnect.