Universal synchronization clock signal derived using single forward and reverse direction clock signals even when phase delay between both signals is greater than one cycle

Abstract

A synchronous bus system includes a clock line having a forward direction clock segment and a reverse direction clock segment connected to each of a plurality of devices. The forward direction clock segment carries a forward direction clock signal, and the reverse direction clock segment carries a reverse direction clock signal. Synchronization clock circuitry, provided in each device, receives the forward direction clock signal and the reverse direction clock signal. Using the received clock signals, the synchronization clock circuitry derives a universal synchronization clock signal which is synchronous throughout all devices. Skew correction circuitry, provided in at least a portion of the devices, corrects for skew between the universal synchronization clock signal and one or more data signals for transferring data between devices.