PROM Programmable Bus Arbitrator
Original Publication Date: 1985-Mar-01
Included in the Prior Art Database: 2005-Feb-18
A PROM (programmable read-only memory)-based table-look-up bus arbitrator arbitrates a common resource between multiple requesters. Programmability of the PROM permits easy changing of the priority scheme, in contrast with current hard-wired arbitrators. The embodiment illustrated in Fig. 1 is for 16 requesters, AA to DD, and uses two levels of arbitration. Shown are four identical Level 1 arbitrators 20. Each one arbitrates between four requesters. A similar Level 2 arbitrator 25 arbitrates between the output request, A, B, C, D, of the four Level 1 arbitrators 20. Each arbitrator includes a PROM programmed with a priority look-up table embodying the desired priority scheme. It is apparent that the plan illustrated in Fig. 1 is not limited to two levels of arbitration for groups of four requesters.