Method and system for preventing device access collision in a

Abstract

Collisions in access to a simulated device are avoided by reserving to one of two or more hardware simulation tests the simulated device. Deadlocks involving requests of multiple tests for reservation of devices are prevented by establishing the order in which such requests are served and requiring that a test must first relinquish reservation of all devices prior to reserving additional devices. Thus, when the additional requests are appended to a queue of pending reservation requests, no test whose requests follow the requests of a second test in the queue can reserve a device requested by the second test. In other words, the situation in which each of two or more tests has reserved a device, reservation of which is required by another of the two or more tests, cannot occur. Starvation is prevented by combining the sorted queue of each reservation phase into a sorted 'round robin' arrangement. Specifically, each collection of requests of a reservation phase are sorted into a request arrival queue and, when the request arrival queue includes all requests of a particular reservation phase, the request arrival queue is appended to the pending request queue. Thus, the lowest priority request of a particular reservation phase of requests is given higher priority than the highest priority request of a subsequent reservation phase. In addition, repeatability of reservation request arbitration is achieved by sorting reservation requests in each request arrival queue according to the respective identifiers of the requesting tests.