Abstract: A system that calibrates timing relationships between signals involved in performing write operations is described. This system includes a memory controller which is coupled to a set of memory chips, wherein each memory chip includes a phase detector configured to calibrate a phase relationship between a data-strobe signal and a clock signal received at the memory chip from the memory controller during a write operation. Furthermore, the memory controller is configured to perform one or more write-read-validate operations to calibrate a clock-cycle relationship between the data-strobe signal and the clock signal, wherein the write-read-validate operations involve varying a delay on the data-strobe signal relative to the clock signal by a multiple of a clock period.

Abstract: According to embodiments of the present invention, an optical modulator control apparatus receives a data signal and determines amplitude and cross-point of the data signal using a full wave detector. The apparatus sums the negative and positive halves of the data signal to determine the amplitude and differences the negative and positive halves of the data signal to determine the cross-point. Measurement of the amplitude may be independent of the cross-point.

Abstract: Optical transponders incorporating an optical dispersion compensator (“ODC”) to perform an adjustable, frequency dependent correction of an optical signal are described and claimed. The ODC is adjusted by a feedback controller that responds to information from at least one signal analyzer. Systems using similar ODC-equipped optical transponders are also described and claimed.

Abstract: An apparatus for optical receiver circuit protection includes a bias source, a bias monitor, and a comparator. The bias source is to provide a bias voltage to an optical receiver. The bias monitor is coupled to measure a current through the optical receiver, where the current changes responsive to received optical energy. A comparator is coupled to the bias monitor, where the comparator has a first state if the current is less than a threshold current level and where the comparator has a second state if the current is greater than the threshold current level. The bias source is coupled to be enabled responsive to the comparator switching to the first state and disabled responsive to the comparator switching to the second state.