Simulation of computer systems with FIFO-discipline interrupt handling

The FIFO (First In First Out) discipline of interrupt processing is widely used in Von Neumann type computers of informational and digital control systems. The goal of implementing such modes of operation — optimization time to data access — is achievable only when there is an adequate model, which describes data processing in the system. The analytical model is worked out with use the fundamental mathematical apparatus of Petri–Markov nets. The initial Petri–Markov model is divided into hierarchical levels in accordance with the number of interrupts in queue for processing. It is shown, that from the current level it is possible to switch both to the previous and to the next interrupt. Dependencies for determine the time of residence on the current level, and the probabilities of switching to conjugate levels are obtained. The method of Petri–Markov model transformation into the semi-Markov process is proposed. It is shown, that semi-Markov process obtained has the binary tree structure. Dependences for determining the time and probabilistic characteristics of wandering through a binary tree, are obtained.