Abstract: An apparatus for accelerated Fiber Channel protocol handshaking and data exchange involves dividing a Fiber Channel arbitrated loop architecture up into a plurality of arbitrated subloops, each of which arbitrates locally using the same fundamentals as the Fiber Channel arbitration protocol but with some slight modifications which do not affect the compatibility of standard Fiber Channel nodes. Each subloop is coupled to a hub port which contains a state machine which does switching function and fill word generation to implement the accelerated protocol by using a plurality of switching, fill word generation and token passing rules. The state machine in each hub port is coupled to its local subloop and to its neighboring hub ports through a single TDMA bus which has timeslots dedicated to carrying broadcast loop and return loop traffic and control token traffic.

Abstract: A synthesized jitter generator employing a novel digital architecture is provided. The apparatus provides period synthesis and controlled sinusoidal and non-sinusoidal jitter modulation functions of a square wave provided at its output. The architecture consists of a coupling of an N+M bit digital accumulator and an N bit synchronous counter to an N bit magnitude compare circuit. The output of the magnitude compare strobes the accumulator when the two inputs are equal in magnitude causing the accumulator to increment synchronously. The output of the magnitude compare is also a digital waveform whose average period is precisely defined by the input word to the accumulator.