Device for transferring data via write or read pointers between two asynchronous subsystems having a buffer memory and plurality of shadow registers

摘要

Device for transferring data between two asynchronous systems communicating via a FIFO memory. The first system comprises a write pointer register and the second system comprises a read pointer register to the FIFO. Each pointer register is associated with a primary shadow register and a secondary shadow register. The primary shadow register is located in the same sub-assembly as the pointer register with which it is associated, and episodically receives a copy of this pointer register. The secondary shadow register is located in the other sub-assembly, and episodically receives a copy of the primary shadow register. Thus, each system has its own pointer register, its associated primary shadow register, and the secondary shadow register associated with the pointer register of the other system.