ADVANCE INFORMATION
COPYRIGHT © INTEL CORPORATION, 1997 May 1997 Order Number: 272928-003
8x930Hx
UNIVERSAL SERIAL BUS HUB
PERIPHERAL CONTROLLER
a73 USB Hub with One Upstream, One
Internal Downstream, and Three
External Downstream Ports on HD/HE
Parts or Four on HF/HG Parts
— Complete Universal Serial Bus Speci-
fication 1.0 Compatibility
— Serves as both USB Hub and USB
Embedded Function (Internal Port)
a73 USB Hub
— Connectivity Management
— Downstream Device
Connect/Disconnect Detection
— Power Management, Including
Suspend and Resume
— Bus Fault Detection and Recovery
— Full and Low Speed Downstream
Device Support
a73 Output Pin for Port Power Switching
a73 Input Pin for Overcurrent Detection
a73 USB Embedded Function
— Supports Isochronous and
Non-isochronous Data
a73 On-chip USB Transceivers
a73 Serial Bus Interface Engine (SIE)
— Packet Decoding/Generation
— CRC Generation and Checking
— NRZI Encoding/Decoding and
Bit-stuffing
a73 Hub FIFO Data Buffers
— One Pair of 16-byte Transmit and
Receive FIFOs
— One 1-byte Transmit Register
a73 Embedded Function FIFO Data Buffers
— Three Pairs of 16-byte Transmit and
Receive FIFOs
— One Pair of Configurable Transmit
and Receive FIFOs (1 Kbyte total)
a73 Automatic Transmit/Receive FIFO
Management
a73 Three USB Interrupt Vectors
— Endpoint Transmit/Receive Done
— Start of Frame/Hub Endpoint Done
— Global Suspend/Resume
a73 Low Clock Mode
a73 User-selectable Configurations
— External Wait State
— External Address Range
—Page Mode
a73 Real-time Wait Function
a73 256-Kbyte External Code/Data Memory
Space
a73 On-chip ROM Options
— 0, 8, or 16 Kbytes
a73 1024 bytes On-chip Data RAM
a73 Four Input/Output Ports
a73 Standard MCS
®
51 UART
a73 Power-saving Idle and Powerdown
Modes
a73 Register-based MCS
®
251 Architecture
a73 Code-compatible with MCS 51 and
MCS 251 Microcontrollers
a73 12-MHz Crystal Operation
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 trans-
ceivers, 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.