The PDIUSBD12 is a cost and feature optimized USB device. It is normally used in microcontroller based systems and communicates with the system microcontroller over the high-speed general purpose parallel interface. It also supports local DMA transfer. This modular approach to implementing a USB interface allows the designer to choose the optimum system microcontroller from the available wide variety. This flexibility cuts down the development time, risks, and costs by allowing the use of the existing architecture and minimize firmware investments. This results in the fastest way to develop the most cost effective USB peripheral solution.