METHODS OF DEBUGGING MULTIPROCESSOR SYSTEM

In a data processing system comprising a plurality of processing elements coupled to a network, a method of single-stepping the processing elements aids in debugging the system. Only one processing element at a time is permitted to execute N steps while its data output is coupled to the network. Once it's finished executing, a time period greater than the maximum propagation delay time of the network is permitted to pass before stepping a succeeding processing element N steps. In another embodiment, the outputs of all processing elements to the network are first disabled, then all processing elements are allowed to execute N steps. Next the system is halted, and, one at a time, the data output of each processing element is coupled to the network, allowing sufficient time for each processing element's output to propagate through the network before coupling the output of a succeeding processing element.