This paper addresses the synchronization problems which arise when real-time signal processing is performed in a multimicroprocessor machine. An experimental machine composed of two specialized microprocessors has been assembled: one to compute correlation and convolution products with a high thruput; the second one is a general purpose microprocessor which efficiently handles independent tasks on its various interrupt levels. The signal processing was decomposed into a sequence of elementary time dependent tasks executed in an appropriate order. Due to microprocessor specialization, the microprocessors had to give assistance to each other, and a tight synchronization between the programs run by each of these was necessary. This machine has been used successfully in data communication applications.