System for providing access to memory in which a second processing unit is allowed to access memory during a time slot assigned to a first processing unit

摘要

Embodiments of the present invention are directed to a microcontroller system incorporating a DMA system and to a method of accessing a memory by a plurality of processing units. In embodiments of the present invention, the microcontroller system includes a plurality of processing units, a DMA module, and an interface to an external memory system. The DMA module controls access to the external memory system by the processing units on a time shared basis by allocating time slots to each of the plurality of processing units. The processing units can access the external memory system during their assigned time slots. Data transfers to and from the memory are accomplished in packets having a fixed maximum size.