Patent ID: 8692600

Claim:
A multi-protocol driver slew rate calibration system for calibrating slew rate control signal values, the system comprising: a first phase rotator configured to generate a first clock signal by phase rotating a input reference signal by a first phase selector amount; a second phase rotator configured to generate a second clock signal by phase rotating the input reference signal by a second phase selector amount; and a calibration controller configured to: initially set the first delay phase amount and the second delay phase amount such that the first clock signal is delayed relative to the second clock signal; determine whether the first clock signal is delayed relative to the second clock signal; if the first clock signal is delayed relative to the second clock signal, change the second phase selector amount that the second phase rotator uses to phase rotate the input reference signal; and if the first clock signal is not delayed relative to the second clock signal, use the first clock signal and the second clock signal to calibrate values of control signals provided to control a slew rate of a calibration clock delay line such that the slew rate of the calibration clock delay line substantially matches a target slew rate.