The M66591 is a general-purpose USB (Universal Serial Bus) device controller compliant with the Universal Serial Bus Specification Revision 2.0 and supports both Hi-Speed and Full-Speed transfer. The USB Hi-Speed and Full-Speed transceiver are built-in, and the M66591 meets control, bulk and interrupt transfer types which are defined in the Universal Serial Bus Specification Revision 2.0. The M66591 has a 3.5K byte FIFO and 7 endpoints (maximum) for data transfer. Further, being equipped with the split bus (DMA interface) which is independent from the CPU bus interface, the M66591 is suitable for use in systems that require large capacity data transfer at Hi-Speed.