Parallel alternating-direction access machine

This paper presents a theoretical study of a model of parallel computations called Parallel Alternating-Direction Access Machine (PADAM). PADAM is an abstraction of the multiprocessor computers ADENA/ADENART and a prototype architecture USC/OMP. The main feature of PADAM is the organization of access to the global memory: (1) the memory modules are arranged as a 2-dimensional array, (2) each processor is assigned to a row and a column, (3) the processors switch synchronously between row and column access modes, and can access any of the assigned modules in each mode without conflicts. Since the PADAM processors have such a restricted access to the partially shared memory, developing tools to enhance flexibility of access to the memory is important. The paper concentrates on these issues.