USB20H04-JD datasheet(20/35 Pages) SMSC

20 / 35 page

4-Port USB 2.0 Hub Controller

Datasheet

Revision 1.63 (03-30-07)

Page 20

SMSC USB20H04

DATASHEET

Chapter 8

Implementation Notes

The following sections consist of select functional explanations to aid in implementing the Hub Controller

into a system.

8.1

Configuration Implementations

The USB20H04 is normally configured by an external EEPROM connected directly to the serial interface.

Typical circuit diagrams are shown below. For a more detailed discussion of the serial interface, including

how to configure the USB20H04 using the SMBus mode, please see Application Note 9.29, "USB20H04 4-

Port USB 2.0 Hub Controller, Configuration Programming". The Application Note also discusses designing

a Hub system that supports In Circuit Programming of the EEPROM.

8.1.1

Interfacing a 2-wire Serial EEPROM

The I

2C EEPROM interface is designed to attach to a single “dedicated” I2C EEPROM. It conforms to the

Standard-mode I

2C Specification (100kbit/s transfer rate and 7-bit addressing) for protocol and electrical

compatibility. The circuit board designer is required to place external pull-up resistors (10K ohm

recommended) on the SDA & SCL lines (per SMBus 1.0 Specification, and EEPROM manufacturer

guidelines) to VDD in order to assure proper operation.

Figure 8.1 - 2-Wire EEPROM Interface

USB20H04-JD Datasheet(PDF) 20 Page - SMSC Corporation