ADVANCE INFORMATION
8x931AA/8x931HA
UNIVERSAL SERIAL BUS
PERIPHERAL CONTROLLERS
■ 8x931AA Hubless USB Peripheral
■ 8x931HA Includes all 8x931AA
Controller
Features
■ On-chip USB Transceivers
■ On-chip Phase-locked loop
■ FIFO Data Buffers
■ 8x931HA USB Hub has One Internal
Downstream, and Four External
Downstream Ports
— Universal Serial Bus Specification
1.0 Compliant
— Two Pairs of 8-byte Transmit and
Receive FIFOs
— Serves as both USB Hub and USB
Embedded Function (Internal Port)
— One Pair of 16-byte Transmit and
Receive FIFOs
■ USB Hub
— Supports Isochronous and
Non-isochronous Data
— Connectivity Management
— Downstream Device
■ Automatic FIFO Management
■ Three USB Interrupt Vectors
— Endpoint Transmit/Receive Done
— Start of Frame
Connect/Disconnect Detection
— Power Management, Including
Suspend and Resume
— Bus Fault Detection and Recovery
— Global Suspend/Resume/USB Reset
— Full and Low Speed Downstream
Device Support
■ Regulated 3V Output for Root Port
Pullup Resistor
■ Hub Endpoint Done Interrupt
■ Output Pin for Port Power Switching
■ Input Pin for Overcurrent Detection
■ Hub FIFO Data Buffers
■ On-chip ROM Options
— 0 or 8 Kbytes
■ 256 bytes On-chip Data RAM
■ Four Input/Output Ports
■ MCS® 51 UART
— One Pair of 8-byte Transmit and
Receive FIFOs
— One 1-byte Transmit Register
■ Three 16-bit Timer/Counters
■ Keyboard Control Interface
■ Four Dedicated LED Driver Outputs
■ 6- or 12-MHz Crystal Operation
— Low Clock Mode (3MHz)
■ Embedded Function FIFO Data Buffers
— Same as the 8x931AA
■ 12-MHz Crystal Operation
— Low Clock Mode (3MHz)
The 8x931AA and 8x931HA USB peripheral controllers are based on the MCS®51 microcontroller. They
consist of standard 8XC51Fx peripherals plus a USB module. The 8x931HA USB module provides both USB
hub and USB embedded function capabilities. The 8x931HA supports USB hub functionality, embedded
function, suspend/resume modes, isochronous/non-isochronous transfers, and is USB rev 1.0 specification
compliant. The USB module contains one internal and 4 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 8x931AA is a hubless USB peripheral controller which contains the same
feature set as the 8x931HA hub controller except for the hub module. The 8x931AA/HA uses the standard
instruction set of the MCS 51 architecture.
COPYRIGHT © INTEL CORPORATION, 1997
November 1997
Order Number: 273108-002