Primary Examiner—Jack B. Harvey
Assistant Examiner—John Travis
Attorney, Agent, or Firm—Blakely, Sokoloff, Taylor & Zafman
A first-come-first-serve ("FCFS") scheduler that routes requests from two or more clients to a single resource. The FCFS scheduler contains a time stamp mechanism which provides a time stamp for each request. The scheduler provides resource access to the client with the oldest generated request and under a predetermined priority scheme in the event of simultaneous requests. The time stamps are generated by adders which add the current value of a time stamp counter with the number of client requests. The time stamp counter is incremented by the output of the adders. The updated value of the counter is decoded into a time stamp output value stored within time stamp registers. A hifind circuit reads the registers and generates an output signal associated with the set of registers, and corresponding client request, with the lowest time stamp. The output signal allows the client to access the resource.
24 Claims, 6 Drawing Sheets