ISP1123 Datasheet, PDF (1/49 Pages) NXP Semiconductors – Universal Serial Bus compound hub

ISP1123
Universal Serial Bus compound hub
Rev. 01 — 5 October 1999
Preliminary specification
1. General description
The ISP1123 is a compound Universal Serial Bus (USB) hub device which complies
with USB Specification Rev. 1.1. It integrates a Serial Interface Engine (SIE), hub
repeater, hub controller, USB data transceivers and a 3.3 V voltage regulator. It has a
configurable number of downstream ports, ranging from 2 to 5, with one port
dedicated to an embedded or non-removable function.
The ISP1123 can be bus-powered, self-powered or hybrid-powered. When it is
hybrid-powered the hub functions are powered by the upstream power supply (V_BUS),
but the downstream ports are powered by an external 5 Volt supply. The low power
consumption in ‘suspend’ mode allows easy design of equipment that is compliant
with the ACPI™, OnNow™ and USB power management requirements.
The ISP1123 has built-in overcurrent sense inputs, supporting individual and ganged
mode overcurrent protection for downstream ports. All ports (including the hub) have
GoodLink™ indicator outputs for easy visual monitoring of USB traffic. The ISP1123
has a serial I²C-bus interface for external EEPROM access and a reduced frequency
(6 MHz) crystal oscillator. These features allow significant cost savings in system
design and easy implementation of advanced USB functionality into PC peripherals.
c
2. Features^c
s High performance USB hub device with integrated hub repeater, hub controller,
Serial Interface Engine (SIE), data transceivers and 3.3 V voltage regulator
s Complies with Universal Serial Bus Specification Rev. 1.1 and ACPI, OnNow and
USB power management requirements
s Downstream port 1 dedicated to a non-removable function, correctly reported in
the related descriptors
s Configurable from 2 to 5 downstream ports with automatic speed detection
s Internal power-on reset and low voltage reset circuit
s Supports bus-powered, hybrid-powered and self-powered application
s Individual or global power switching for downstream ports
s Individual or ganged port overcurrent protection with built-in sense circuits
s 6 MHz crystal oscillator with on-chip PLL for low EMI
s Visual USB traffic monitoring (GoodLink™) for hub and downstream ports
s I²C-bus interface to read vendor ID, product ID and configuration bits from
external EEPROM