Abstract: In at least some embodiments, a system comprises two processor cores, an external memory coupled to the two processor cores, and a program that is executable at least in part by one or both of the processing cores. When executed by one of the processor cores the program causes the processor core to map a private region of the external memory, which is accessible only to one of the two processor cores, to a pre-reserved region of memory addresses used by the other processor core. The mapping permits the processor core that does not have direct access to the private memory region of the other processor core to access data stored in the private region. In at least some embodiments, the mapped memory can be subsequently unmapped and re-mapped to another private memory region at run-time.