The ISP1181 is a Universal Serial Bus (USB) interface device which complies with Universal Serial Bus Specification Rev. 1.1. It provides full-speed USB communication capacity to microcontroller or microprocessor-based systems. The ISP1181 communicates with the system's microcontroller or microprocessor through a high-speed general-purpose parallel interface. The fully autonomous Direct Memory Access (DMA) operation - auto download, auto repeat, auto execution - removes the need for the device to re-enable or re-initialize the DMA operation every time.