1. A method for synchronizing multiple processing units, comprising the steps of: configuring a synchronization register in a target processing unit so that its content is overwritten only by bits that are set in words written in the synchronization register; assigning a distinct bit position of the synchronization register to each processing unit; executing a program thread in each processing unit; when the program thread of a current processing unit reaches a synchronization point writing in the synchronization register of the target processing unit a word in which the bit position assigned to the current processing unit is set, and suspending the program thread; and when all the bits assigned to the processing units are set in the synchronization register, resuming the suspended program threads.