The 8x930Hx USB hub peripheral controller is based on the MCS 251 microcontroller. It consists of standard 8XC251Sx peripherals plus a USB module. The USB module provides both USB hub and USB embedded function capabilities. The 8x930Hx supports USB hub functionality, embedded function, suspend/resume modes, isochronous/non-isochronous transfers, and it is fully USB rev 1.0 specification compliant. The USB module contains one internal and three (or four) external downstream ports and integrates the USB transceivers, serial bus interface engine (SIE), hub interface unit (HIU), function interface unit (FIU), and transmit/receive FIFOs. The 8x930Hx uses the standard instruction set of the MCS 251 architecture, which is binary code compatible with the MCS 51 architecture. COPYRIGHT INTEL CORPORATION, 1997