1. Field of the Invention
This invention is related to the field of integrated circuits and, more particularly, to direct memory access (DMA) in systems comprising one or more integrated circuits.
2. Description of the Related Art
In a typical system that includes one or more processors, memory, and input/output (I/O) devices or interfaces, direct memory access (DMA) transfers are often used to transfer data between the I/O and the memory. In some systems, individual DMA circuitry is included in each I/O device or interface that uses DMA. In other systems, one or more I/O devices may share DMA circuitry.
Some systems also include a “data mover” that can be used to copy data from one area of memory to another. The data mover may offload the processors, which would otherwise have to execute instructions to perform the data movement (e.g. reading and writing data at the width that the processor uses, typically 32 bits or 64 bits at a time). The programming model for the data mover is typically different than the DMA programming model, which is geared to communicating between I/O devices and memory.