SMSC USB2502 User Manual

USB2502

2-Port USB 2.0 Hub
Controller

PRODUCT FEATURES

 Integra ted USB 2.0 Compatible 2-Port Hub

— High-Speed (480Mbits/s), Full-Speed (12Mbits/s) and

Low-Speed (1.5Mbits/s) compatible
— Full power management with ganged power control
— Detects Bus-Power/Self-Power source and changes

mode automatically

 Co mplete USB Specification 2.0 Compatibility

— Includes USB 2.0 Transceivers

 VID/PID/DID, and Port Configuration for Hub via:

— Single Serial I2C EEPROM
— SMBus Slave Port

 De fault VID/PID/DID, allows functionality when

configuration EEPROM is absent

 Ha rdware Strapping options allow for configuration

without an external EEPROM or SMBus Host

Datasheet

 On-Boa rd 24MHz Crystal Driver Circuit or 24 MHz

external clock driver

 Interna l PLL for 480MHz USB 2.0 Sampling
 Interna l 1.8V Linear Voltage Regulator
 Integ rated USB termination and Pull-up/Pull-down

resistors

 Interna l Short Circuit protection of USB differential

signal pins

 Ba sic single-color LED support
 1 .8 Volt Low Power Core Operation
 3 .3 Volt I/O with 5V Input Tolerance
 3 6 Pin QFN or 48 Pin TQFP lead-free RoHS

compliant package

SMSC USB2502 DATASHEET Revision 2.3 (08-27-07)

2-Port USB 2.0 Hub Controller

Datasheet

ORDER NUMBERS:

USB2502-AEZG FOR 36 PIN LEAD-FREE ROHS COMPLIANT QFN PACKAGE; USB2502-HT FOR 48 PIN LEAD-

FREE ROHS COMPLIANT TQFP PACKAGE

80 ARKAY DRIVE, HAUPPAUGE, NY 11788 [phone], FAX [phone]

Copyright © 2007 SMSC or its subsidiaries. All rights reserved.
Circuit diagrams and other information relating to SMSC products are included as a mean s of illustrating typical applications. Conse quently, complete information sufficient for

construction purposes is not necessarily given. Although the information has been checked and is believed to be accurate, no responsibility is assumed for inaccuracies. SMSC
reserves the right to make changes to specifications and product descriptions at any time without notice. Contact your local SMSC sales office to obtain the latest specifications
before placing your product order. The provision of this information does not convey to the purchaser of the described semiconductor devices any licenses under any patent
rights or other intellectual property rights of SMSC or others. All sales are expressly conditional on your agreement to the terms and conditions of the most recently da ted
version of SMSC's standard Terms of Sale Agreement dated before the date of your order (the "Terms of Sale Agreement"). The product may contain design defects or errors
known as anomalies which may cause the product's functions to deviate from published specifications. Anomaly sheets are available upon request. SMSC products are not
designed, intended, authorized or warranted for use in any life support or other application where product failure could cause or contribute to personal injury or severe property
damage. Any and all such uses without prior written approval of an Officer of SMSC and further testing and/or modification will be fully at the risk of the customer. Copies of
this document or other SMSC literature, as well as the Terms of Sale Agreement, may be obtained by visiting SMSC’s website at http://www.smsc.com. SMSC is a registered
trademark of Standard Microsystems Corporation (“SMSC”). Product names and company names are the trademarks of their respective holders.

SMSC DISCLAIMS AND EXCLUDES ANY AND ALL WARRANTIES, INCLUDING WITHOUT LIMITATION ANY AND ALL IMPLIED WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE, TITLE, AND AGAINST INFRINGEMENT AND THE LIKE, AND ANY AND ALL WARRANTIES ARISING FROM ANY COURSE
OF DEALING OR USAGE OF TRADE. IN NO EVENT SHALL SMSC BE LIABLE FOR ANY DIRECT, INCIDENTAL, INDIRECT, SPECIAL, PUNITIVE, OR CONSEQUENTIAL
DAMAGES; OR FOR LOST DATA, PROFITS, SAVINGS OR REVENUES OF ANY KIND; REGARDLESS OF THE FORM OF ACTION, WHETHER BASED ON CONTRACT;
TORT; NEGLIGENCE OF SMSC OR OTHERS; STRICT LIABILITY; BREACH OF WARRANTY; OR OTHERWISE; WHETHER OR NOT ANY REMEDY OF BUYER IS HELD
TO HAVE FAILED OF ITS ESSENTIAL PURPOSE, AND WHETHER OR NOT SMSC HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES.

Revision 2.3 (08-27-07) 2 SMSC USB2502

DATASHEET

2-Port USB 2.0 Hub Controller

Datasheet

Table of Contents

Chapter 1 General Description. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

1.1 OEM Selectable Features. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

Chapter 2 Pin Table 2-Port. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

Chapter 3 Pin Configuration 2-Port Hub . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

Chapter 4 2-Port Hub Block Diagram. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

Chapter 5 Functional Block Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16

5.1 2-Port Hub . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16

5.1.1 Hub Configuration Options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16

5.1.2 VBus Detect. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18

5.2 EEPROM Interface. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

5.2.1 I2C EEPROM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

5.2.2 In-Circuit EEPROM Programming. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

5.2.3 EEPROM DATA . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

5.3 SMBus Slave Interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24

5.3.1 Bus Protocols . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24

5.3.2 Invalid Protocol Response Behavior . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25

5.3.3 General Call Address Response . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25

5.3.4 Slave Device Time-Out . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26

5.3.5 Stretching the SCLK Signal. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26

5.3.6 SMBus Timing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26

5.3.7 Bus Reset Sequence. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26

5.3.8 SMBus Alert Response Address. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26

5.3.9 Internal SMBus Memory Register Set . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26

5.4 Default Configuration Option: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32

5.5 Default Strapping Options: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32

5.6 Reset . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32

5.6.1 External Hardware RESET_N . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33

5.6.2 USB Bus Reset . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36

Chapter 6 XNOR Test . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37

Chapter 7 DC Parameters. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38

7.1 Maximum Guaranteed Ratings. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38

7.2 Recommended Operating Conditions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39

Chapter 8 AC Specifications. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42

8.1 Oscillator/Clock. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42

8.1.1 SMBus Interface:. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42

8.1.2 I2C EEPROM: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42

8.1.3 USB 2.0 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42

Chapter 9 Package Outlines . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43

SMSC USB2502 3 Revision 2.3 (08-27-07)

DATASHEET

2-Port USB 2.0 Hub Controller

Datasheet

List of Tables

Table 2.1 2-Port Pin Table for 36-QFN . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

Table 2.2 2-Port Pin Table for 48-TQFP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

Table 4.1 2-Port Hub Pin Descriptions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

Table 4.2 SMBus or EEPROM Interface Behavior . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

Table 4.3 Miscellaneous Pins . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

Table 4.4 Power, Ground, and No Connect. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

Table 4.5 Buffer Type Descriptions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

Table 5.1 User-Defined Descriptor Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

Table 5.2 SMBus Write Byte Protocol . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25

Table 5.3 SMBus Read Byte Protocol. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25

Table 5.4 SMBus Slave Interface Register Map . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26

Table 5.5 Reset_N Timing for Default/Strap Option Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33

Table 5.6 Reset_N Timing for EEPROM Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34

Table 5.7 Reset_N Timing for SMBus Mode. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35

Table 7.1 DC Electrical Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39

Table 9.1 48 Pin TQFP Package. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44

Revision 2.3 (08-27-07) 4 SMSC USB2502

DATASHEET

2-Port USB 2.0 Hub Controller

Datasheet

List of Figures

Figure 3.1 2-Port 36-Pin QFN . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

Figure 3.2 2-Port 48-Pin TQFP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10

Figure 4.1 2-Port Block Diagram. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

Figure 5.1 LED Strapping Option . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32

Figure 5.2 Reset_N Timing for Default/Strap Option Mode. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33

Figure 5.3 Reset_N Timing for EEPROM Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34

Figure 5.4 Reset_N Timing for SMBus Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35

Figure 9.1 36 Pin QFN Package . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43

Figure 9.2 48 Pin TQFP Package Outline (7x7x1.4 mm body, 2mm Footprint) . . . . . . . . . . . . . . . . . . . 44

SMSC USB2502 5 Revision 2.3 (08-27-07)

DATASHEET

Chapter 1 General Description

The SMSC 2-Port Hub is fully compliant with the USB 2.0 Specification and will attach to a USB host
as a Full-Speed Hub or as a Full-/High-Speed Hub. The 2-Port Hub supports Low-Speed, Full-Speed,
and High-Speed (if operating as a High-Speed Hub) downstream devices on all of the enabled
downstream ports.

2-Port USB 2.0 Hub Controller

Datasheet

The Hub works with an external USB power distribution switch device to control V
downstream ports, and to limit current and sense over-current conditions.

All required resistors on the USB ports are integrated into the Hub. This includes all seri es termination
resistors on D+ and D– pins and all require d pull-down and pull-up resistors on D+ and D– pins. The
over-current sense inputs for the downstream facing ports have internal pull-up resistors.

Throughout this document the upstream facing port of the hub will be referred to as the upstream port,
and the downstream facing ports will be called the downstream ports.

1.1 OEM Selectable Features

A default configuration is available in the USB2502 following a reset. This configuration may be
sufficient for some applications. Strapping option pins make it possible to modify a limited sub-set of
the configuration options.

The USB2502 may also be configured by an external EEPROM or a microcontroller. When using the
microcontroller interface, the Hub appears as an SMBus slave device. If the Hub is pin-strapped for
external EEPROM configuration but no external EEPROM is present, then a value of ‘0’ will be written
to all configuration data bit fields (the hub will attach to the ho st with all ‘0’ values).

The 2-Port Hub supports several OEM selectable features:

 Operation as a Self-Powered USB Hub or as a Bus-Powered USB Hub.
 Operation as a Dynamic-Powered Hub (Hub operate s as a Bus-Powered device if a local power

source is not available and switches to Self-Powered opera tion when a local power source is
available).

 Optional OEM configuration via I2C EEPROM or via the industry standard SMBus interface from

an external SMBus Host.

 Compound device support (port is permanently hardwired to a down strea m USB perip heral device ).
 Hardware strapping options enable configuration of the following feature s.

Non-Removable Ports
Port Power Polarity (active high or active low logic)

switching to

BUS

Revision 2.3 (08-27-07) 6 SMSC USB2502

DATASHEET

2-Port USB 2.0 Hub Controller

Datasheet

Chapter 2 Pin Table 2-Port

Table 2.1 2-Port Pin Table for 36-QFN

UPSTREAM USB 2.0 INTERFACE (3 PINS)

USBDP0 USBDN0 VBUS_DET

2-PORT USB 2.0 INTERFACE (10 PINS)

USBDP1 USBDN1 USBDP2 USBDN2

GR1/

NON_REM0

PRTPWR OCS_N

SDA/SMBDATA SCL/SMBCLK/

XTAL1/CLKIN XTAL2 RESET_N SELF_PWR

ATEST/

REG_EN

GR2/

NON_REM1

SERIAL PORT INTERFACE (3 PINS)

CFG_SEL0

MISC (7 PINS)

CLKIN_EN TEST

POWER, GROUND (13 PINS)

PRTPWR_POL RBIAS

CFG_SEL1

SMSC USB2502 7 Revision 2.3 (08-27-07)

DATASHEET

2-Port USB 2.0 Hub Controller

Table 2. 2 2-Port Pin Table for 48-TQFP

UPSTREAM USB 2.0 INTERFACE (3 PINS)

USBDP0 USBDN0 VBUS_DET

2-PORT USB 2.0 INTERFACE (10 PINS)

USBDP1 USBDN1 USBDP2 USBDN2

Datasheet

GR1/

NON_REM0

GR2/

NON_REM1

PRTPWR_POL RBIAS

PRTPWR OCS_N

SERIAL PORT INTERFACE (3 PINS)

SDA/SMBDATA SCL/SMBCLK

CFG_SEL1

CFG_SEL0

MISC (7 PINS)

XTAL1/CLKIN XTAL2 RESET_N SELF_PWR

ATEST/

CLKIN_EN TEST

REG_EN

POWER, GROUND AND NO CONNECT (25 PINS)

Revision 2.3 (08-27-07) 8 SMSC USB2502

DATASHEET

2-Port USB 2.0 Hub Controller

Datasheet

Chapter 3 Pin Configuration 2-Port Hub

26 VSS

25 VBUS_DET

24 RESET_N

23 TEST

22 CLKIN_EN

21 CFG_SEL1

20 SCL/SMBCLK/CFG_SEL0

19 SDA/SMBDATA

18 VDD18
17 VSS
16 SELF_PWR
15 OCS_N
14 PRTPWR
13 PRTPWR_POL
12 GR2/NON_REM1
11 GR1/NON_REM0
10 VSS

VDD33CR 28

VSS 29

XTAL2 30

XTAL1/CLKIN 31

VDDA18PLL 32
VDDA33PLL 33

ATEST/REG_EN 34

RBIAS 35

VSS 36

27 VDD18

SMSC

USB2502

(Top View QFN-36)

Thermal Slug

(must be connected to VSS)

VSS 4

VDDA33 1

USBDP0 2

USBDN0 3

USBDN1 5

VDDA33 7

USBDP1 6

USBDP2 8

USBDN2 9

Indicates pins on the bottom of the device.

Figure 3.1 2-Port 36-Pin QFN

SMSC USB2502 9 Revision 2.3 (08-27-07)

DATASHEET

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Figure 3.2 2-Port 48-Pin TQFP

Revision 2.3 (08-27-07) 10 SMSC USB2502

DATASHEET

2-Port USB 2.0 Hub Controller

Datasheet

Chapter 4 2-Port Hub Block Diagram

8SVWUHDP

V

BUS

Bus-Power

'HWHFW

Downstream PHY #1

Downstream

USB Data

Upstream
USB Data

Upstream

PHY

Repeater

24 MHz

Crystal

3.3V

PLL

1.8V Reg

SIE

Transaction Translator

Routing Logic

OC Sense

Switch Driver

LED Driver

Strapping Options

OC

Sense

Switch/LED
Driver/optís

To EEPROM or

SMBus Master

1.8V

Serial

Interface

Controller

Port

Controller

Downstream PHY #2

Downstream

USB Data

SCKSD

Figure 4.1 2-Port Block Diagram

Ta ble 4.1 2-Port Hub Pin Descriptions

NAME SYMBOL TYPE FUNCTION

UPSTREAM USB 2.0 INTERFACE

USB Bus Data USBDN0

IO-U These pins connect to the upstream USB bus data signals.

USBDP0

Detect Upstream

VBUS Power

VBUS_DET I/O8 Detects state of Upstream VBUS power. The SMSC Hub

monitors VBUS_DET to determine when to assert the
internal D+ pull-up resistor (signalling a connect event).

When designing a detachable hub, this pin must be
connected to the VBUS power pin of the USB port that is
upstream of the hub. (Use of a weak pull-down resist or is
recommended.)

For self-powered applications with a permanently attached
host, this pin must be pulled-up to either 3.3V or 5 .0V
(typically VDD33).

SMSC USB2502 11 Revision 2.3 (08-27-07)

DATASHEET

Table 4.1 2-Port Hub Pin Descriptions (continued)

NAME SYMBOL TYPE FUNCTION

2-PORT USB 2.0 HUB INTERFACE

2-Port USB 2.0 Hub Controller

Datasheet

High-Speed USB

Data

USB Power

Enable

Port [2:1] Green

LED

&

Port Non-

Removable

strapping option.

USBDN[2:1]
USBDP[2:1]

IO-U These pins connect to the downstream USB peripheral

devices attached to the Hub’s ports.

PRTPWR O8 Enables power to USB peripheral devices (downstream).

The active signal level of the PRTPWR pin is determined by
the Power Polarity Strapping function of the PRTPWR_POL
pin.

GR[2:1]/

NON_REM[1:0]

I/O8 Green indicator LED for ports 2 and 1. Will be active lo w

when LED support is enabled via EEPROM or SMBus.
If the hub is configured by the internal default conf iguration ,

these pins will be sampled at the rising edge of RESET_N
(see the applicable RESET_N timing table in Section 5.6.1)
to determine if ports [2:1] contain permanently attached
(non-removable) devices. Also, the active state of the LED’s
will be determined as follows:

NON_REM[1:0] = ‘00’, All ports are removable,
GR2 is active high,
GR1 is active high.

NON_REM1:0] = ‘01’, Port 1 is non-removable,
GR2 is active high,
GR1 is active low.

NON_REM[1:0] = ‘10’, Ports 1 & 2 are non-removable,
GR2 is active low,
GR1 is active high.

NON_REM[1:0] = ‘11’, Ports 1 & 2 are non-removable,
GR2 is active low,
GR1 is active low.

Port Power

Polarity strapping.

PRTPWR_POL I/O8 Port Power Polarity strapping determination for the active

signal polarity of the PRTPWR pin.
While RESET_N is asserted, the logic state of this pin will

(though the use of internal combinatorial logic) d etermine
the active state of the PRTPWR pin in order to ensure that
downstream port power is not inadvertently enabl ed to
inactive ports during a hardware reset.

On the rising edge of RESET_N (see the applicable
RESET_N timing table in Section 5.6.1), the logic value will
be latched internally, and will retain the active signal polarity
for the PRTPWR pin.

‘1’ = PRTPWR pin has an active ‘high’ polarity
‘0’ = PRTPWR pin has an active ‘low’ polarity

Over Current

Sense

USB Transceiver

Bias

Revision 2.3 (08-27-07) 12 SMSC USB2502

OCS_N IPU Input from external current monitor indicating an over-

current condition. {Note: Contains internal pull-up to 3.3V
supply}

RBIAS I-R A 12.0kΩ (+/− 1%) resistor is attached from ground to this

pin to set the transceiver’s intern al bias settings.

DATASHEET

2-Port USB 2.0 Hub Controller

Datasheet

Table 4.1 2-Port Hub Pin Descriptions (continued)

NAME SYMBOL TYPE FUNCTION

SERIAL PORT INTERFACE

Serial Data/SMB

Data

Serial Clock/SMB

Clock

&

Config Select 0

Configuration
Programming

Select

SDA/SMBDATA IOSD12 (Serial Data)/(SMB Data) signal.

SCL/SMBCLK/

CFG_SEL0

IOSD12 (Serial Clock)/(SMB Clock) signal. This mult ifunction pin is

read on the rising edge of RESET_N (see the applicable
RESET_N timing table in Section 5.6.1) and will determine
the hub configuration method as described in Table 4.2.

CFG_SEL1 I This pin is read on the rising edge of RESET_N (see the

applicable RESET_N timing table in Section 5.6.1) and wi ll
determine the hub configuration metho d as described in

Table 4.2.

Table 4.2 SMBus or EEPROM Interface Behavior

CFG_SEL1 CFG_SEL0 SMBus or EEPROM interface behavior.

00Reserved
0 1 Configured as an SMBus slave for external download of user-

defined descriptors. SMBus slave address is 0101100
1 0 Internal Default Configuration via strapping options.
1 1 2-wire (I2C) EEPROMS are supported,

Table 4.3 Miscellaneous Pins

NAME SYMBOL TYPE FUNCTION

Crystal

Input/External

Clock Input

XTAL1/

CLKIN

ICLKx 24MHz crystal or external clock input.

This pin connects to either one terminal of the crystal or
to an external 24MHz clock when a crystal is not used.

Crystal Output XTAL2 OCLKx 24MHz Crystal

This is the other terminal of the crystal, or left
unconnected when an external clock source is used to
drive XTAL1/CLKIN. It must not be used to drive any
external circuitry other than the crystal circuit.

Clock Input

Enable

CLKIN_EN I Clock In Enable:

Low = XTAL1 and XTAL2 pins configured for u se with
external crystal
High = XTAL1 pin configured as CLKIN, and must be
driven by an external CMOS clock.

RESET Input RESET_N IS This active low signal is used by the system to reset the

chip. The minimum active low pulse is 1us.

Self-Power /

Bus-Power

Detect

SELF_PWR I Detects availability of local self-power source.

Low = Self/local power source is NOT available (i.e., Hub
gets all power from Upstream USB VBus).
High = Self/local power source is available.

TEST Pin TEST IPD Used for testing the chip. User must treat as a no-

connect or connect to ground.

SMSC USB2502 13 Revision 2.3 (08-27-07)

DATASHEET

2-Port USB 2.0 Hub Controller

Table 4.3 Miscellaneou s Pin s (continued)

NAME SYMBOL TYPE FUNCTION

Datasheet

Analog Test

&

Internal 1.8V

voltage

regulator

enable

NAME SYMBOL TYPE FUNCTION

VDDCORE3P3 VDD33CR +3.3V I/O Power.

VDD1P8 VDD18 +1.8V core power.

VDDAPLL3P3 VDDA33PLL +3.3V Filtered analog power for the internal PL L

A TEST/

REG_EN

AIO This signal is used for testing the analog section of the

Table 4.4 Power, Ground, and No Connect

chip, and to enable or disable the internal 1. 8v regulato r.
This pin must be connected to VDDA33 to e nable the

internal 1.8V regulator, or to VSS to disable the internal
regulator.

When the internal regulator is enabled, the 1 .8V power
pins must be left unconnected, except for the required
bypass capacitors.When the PHY is in test mode, the
internal regulator is disabled and the ATEST pin
functions as a test pin.

If the internal core 1.8V regulator is enabled, then this pin
acts as the regulator input

If the internal regulator is enabled, then VDD18 pin 27
must have a 4.7
capacitor to VSS

μF (or greater) ±20% (ESR <0.1Ω)

If the internal PLL 1.8V regulator is enabled, then this pin
acts as the regulator input

VDDAPLL1P8 VDDA18PLL +1.8V Filtered analog power for internal PLL.

If the internal regulator is enabled, then this pin must
have a 4.7
to VSS

VDDA3P3 VDDA33 +3.3V Filtered analog power.

VSS VSS Ground.

Table 4.5 Buffer Type Descriptions

BUFFER DESCRIPTION

I Input.
IPD Input, with a weak Internal pul l-down.
IPU Input, with a weak Internal pul l-up.

IS Input with Schmitt trigger.

I/O8 Input/Output 8mA

O8 Output 8mA

μF (or greater) ±20% (ESR <0.1Ω) capacitor

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2-Port USB 2.0 Hub Controller

Datasheet

Table 4.5 Buffer Type Descriptions (continued)

BUFFER DESCRIPTION

IOSD12 Open drain….12mA sink with Schmitt trigge r, and must meet I2C-Bus Specification Version 2.1

requirements.

ICLKx XTAL Clock Input

OCLKx XTAL Clock Output

I-R RBIAS

IO-U Defined in USB Specification.

Note: Meets USB 1.1 requirements when operating as a 1.1-compliant device and meets USB

2.0 requirements when operating as a 2.0-compliant device.

AIO Analog Input/output. Per PHY test requirements.

SMSC USB2502 15 Revision 2.3 (08-27-07)

DATASHEET

Chapter 5 Functional Block Description

5.1 2-Port Hub

SMSC’s USB 2.0 2-Port Hub is fully specification compliant to the Universal Serial Bus Specification
Revision 2.0 April 27,2000 (12/7/2000 and 5/28/2002 Errata). Please reference Chapter 11 (Hub
Specification) for general details regarding Hub operation and functionality.

For performance reasons, the 2-Port Hub provides 1 Transaction Translator (TT) per port (defined as
Multi-TT configuration), divided into 4 non-periodic buffers per TT.

5.1.1 Hub Configuration Options

The SMSC Hub supports a large number of features and must be configured in order to correctly
function when attached to a USB host controller. There are three principal ways to configure the hub:
SMBus, EEPROM, or by internal default settings. In all cases, the configuration method will be
determined by the CFG_SEL1 and CFG_SEL0 pins immediately after RESET_N negation.

5.1.1.1 Vendor ID

Is a 16-bit value that uniquely identifies the Vendor of the user device (assigned by USB-Interface
Forum). This field is set by the OEM using either the SMBus or EEPROM interface options. When
using the internal default option, SMSC’s VID (see Table 5.1) will be reported.

2-Port USB 2.0 Hub Controller

Datasheet

5.1.1.2 Product ID

Is a 16-bit value that the Vendor can assign that uniquely identifies this particular product (assigned
by OEM). This field is set by the OEM using either the SMBus or EEPROM interface options. When
using the internal default option, SMSC’s PID designation of (see Table 5.1) will be reported .

5.1.1.3 Device ID

Is a 16-bit device release number in BCD format (assigned by OEM). This field is set by the OEM
using either the SMBus or EEPROM interface options. When using the internal default option, SMSC’s
DID designation of (see Table 5.1) will be reported.

5.1.1.4 Self-Powered/Bus-Powered

The Hub is either Self-Powered (draws less than 2mA of upstream bus power) or Bus-Powered
(limited to a 100mA maximum of upstream power prior to being configured by th e host controller).

When configured as a Bus-Powered device, the SMSC Hub consumes less than 100mA of current
prior to being configured. After configuration, the Bus-Powered SMSC Hub (along with all associated
hub circuitry, any embedded devices if part of a compound device, and 100mA per externally available
downstream port) must consume no more than 500mA of upstream VBUS current. The current
consumption is system dependent, and the OEM must ensure that the USB 2.0 specifications are not
violated.

When configured as a Self-Powered device, <1mA of upstream VBUS current is consumed and all 7
ports are available, with each port being capable of sourcing 500mA of current.

This field is set by the OEM using either the SMBus or EEPROM interface options. When using the
internal default option, the SELF_PWR pin det ermines the Self-powered or Bus-powered status.

Please see the description under Dynamic Power for the self/bus power fu nctionality when dynamic
power switching is enabled.

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2-Port USB 2.0 Hub Controller

Datasheet

5.1.1.5 High-Speed Disable

Allows an OEM to force the Hub to configure as a Full-Speed device only (i.e. High-Speed not
available).

This field is set by the OEM using either the SMBus or EEPROM in terface options.

5.1.1.6 EOP Disable

During FS operation only, this permits the Hub to send EOP if no downstream traffic is detected at
EOF1. See Section 11.3.1 of the USB 2.0 Specification for additional details.

This field is set by the OEM using either the SMBus or EEPROM in terface options.

5.1.1.7 Current Sensing

Selects current sensing as all ports ganged, or none.
This field can be set by the OEM using either the SMBus or EEPROM interface options.When using

the internal default option, the SELF_PWR pin determines if current sensing will be ganged, or none
(ganged if self-powered, none if bus-powere d)

5.1.1.8 Compound Device

Allows the OEM to indicate that the Hub is part of a compound (see the USB Specification for
definition) device. The applicable port(s) must a lso be defined as having a “Non-Removable Device”.

This field is set by the OEM using either the SMBus or EEPROM in terface options.
Note: When configured via strapping options, decl aring a port as non-remov able automatically ca uses

the hub controller to report that it is part of a compound d evice.

5.1.1.9 Non-Removable Device

Informs the Host if one of the active ports has a permanent device that is undetachable from the Hub.
(Note: The device must provide its own descriptor data.)

This field is set by the OEM using either the SMBus or EEPROM interface options. When using the
internal default option, the NON_REM[1:0] pins will designate the appropriate ports as being non­removable.

5.1.1.10 Self-Powered Port DISABLE

During Self-Powered operation, this selects the ports which will be permanently disabled, and are not
available to be enabled or enumerated by a Host Controller. The disabled ports must be in decreasing
order starting with port 2.

This field is set by the OEM using either the SMBus or EEPROM in terface options.

5.1.1.11 Bus-Powered Port DISABLE

During Bus-Powered operation, this selects the ports which will be permanently disabl ed, and are not
available to be enabled or enumerated by a Host Controller. The disabled ports must be in decreasing
order starting with port 2.

This field is set by the OEM using either the SMBus or EEPROM in terface options.

5.1.1.12 Dynamic Power

Controls the ability of the 2-Port Hub to automatically change from Self-Powered operation to Bus­Powered operation if the local power source is removed or is unavailable (and from Bus-Powered to
Self-Powered if the local power source is restored). {Note: If the local po wer source is available, the
2-port Hub will always switch to Self-Powered operati on.}

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DATASHEET

When Dynamic Power switching is enabled, the Hub detects the availability of a local power source
by monitoring the external SELF_PWR pin. If the Hub detects a change in power source availability,
the Hub immediately disconnects and removes power from all downstream devices and disconnects
the upstream port. The Hub will then re-attach to the upstream port as either a Bus-Powered Hub (if
local-power in unavailable) or a Self-Powered Hub (if local power is availa ble).

This field is set by the OEM using either the SMBus or EEPROM in terface options.

5.1.1.13 Over-Current Timer

The time delay (in 2ms increments) for an over-current condition to persist before it is reported to the
Host.

This field is set by the OEM using either the SMBus or EEPROM in terface options.

5.1.1.14 Self-Powered Max Power

When in Self-Powered configuration, Sets value in 2mA increments.
This field is set by the OEM using either the SMBus or EEPROM in terface options.

5.1.1.15 Bus-Powered Max Power

When in Bus-Powered configuration, Sets value in 2mA increments.

2-Port USB 2.0 Hub Controller

Datasheet

This field is set by the OEM using either the SMBus or EEPROM in terface options.

5.1.1.16 Self-powered Hub Controller Current

When in Self-Powered configuration, Maximum current requirements of the Hub Controller in 2mA
increments.

This field is set by the OEM using either the SMBus or EEPROM in terface options.

5.1.1.17 Bus-Powered Hub Controller Current

When in Bus-Powered configuration, Maximum current requirements of the Hub Controller in 2mA
increments.

This field is set by the OEM using either the SMBus or EEPROM in terface options.

5.1.1.18 Power-On Timer

Time (in 2ms intervals) from the time power-on sequence begins on a port until power is good on that
port. System software uses this value to determine how long to wait before accessing a powered-on
port.

This field is set by the OEM using either the SMBus or EEPROM in terface options.

5.1.1.19 Power Switching Polarity

The selection of active state “polarity” for the PRTPWR2 pin i s made by a strapping option only.

5.1.2 VBus Detect

According to Section 7.2.1 of the USB 2.0 Specification, a downstream port can never provide power
to its D+ or D- pull-up resistors unless the upstream port’s VBUS is in the asserted (powered) state.
The VBUS_DET pin on the Hub monitors the state of the upstream VBUS signal and will not pull- up
the D+ or D- resistor if VBUS is not active. If VBUS goes from an active to an inactive state (Not
Powered), Hub will remove power from the D+ or D- pull-up resi stor within 10 seconds.

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2-Port USB 2.0 Hub Controller

Datasheet

5.2 EEPROM Interface

The SMSC Hub can be configured via a 2-wire (I2C) EEPROM. (Please see Table 4.1, "7-Port Hub

Pin Descriptions" for specific details on how to enable the I2C EEPROM option).

The Internal state-machine will, (when configured for EEPROM support) read the external EEPROM
for configuration data. The hub will then “attach” to the upstream USB host.

Please see Table 5.1 User-Defined Descriptor Data for a list of data fields available.

5.2.1 I2C EEPROM

The I2C EEPROM interface implements a subset of the I2C Master Specification (Please refer to the
Philips Semiconductor Standard I2C-Bus Specification for details on I2C bus protocols). The Hub’s I2C
EEPROM interface is designed to attach to a single “dedicated” I2C EEPROM, and it conforms to the
Standard-mode I2C Specification (100kbit/s transfer rate and 7-bit addressing) for protocol and
electrical compatibility.

Note: Extension s to the I2C Specification are not supported.

The Hub acts as the master and generates the serial clo ck SCL, controls the bus access (determines
which device acts as the transmitter and which device acts as the receiver), and generates the START
and STOP conditions.

5.2.1.1 Implementation Characteristics

Please refer to the MicroChip 24AA00 DataSheet for Protocol and Programming specifics.

5.2.1.2 Pull-Up Resistor

The Circuit board designer is required to place external pul l-up resistors (10KΩ recommended) on the
SDA/SMBDATA & SCL/SMBCLK/CFG_SELO lines (per SMBus 1.0 Specification, and EEPROM
manufacturer guidelines) to Vcc in order to assure proper operation.

5.2.1.3 I2C EEPROM Slave Address

Slave address is 1010000.

Note: 10-b it addressing is NOT supported.

5.2.2 In-Circuit EEPROM Programming

The EEPROM can be programmed via ATE by pulling RESET_N low (which tri-states the Hub’s
EEPROM interface and allows an external source to program the EEPROM).

5.2.3 EEPROM DATA

Table 5.1 User-De fined Descriptor Data

DEFAULT

CFG
BUS

(HEX) DESCRIPTION

FIELD

BYTE
MSB:

LSB

SIZE

(BYTES)

DEFAULT

CFG

SELF

(HEX)

VID 1: 0 2 0424 0424 Vendor ID (assigned by USB-IF).
PID 3: 2 2 2502 2502 Product ID (assigned by Manufacturer).

DID 5:4 2 0 000 0000 Device ID (assigned by Manufacturer).

SMSC USB2502 19 Revision 2.3 (08-27-07)

DATASHEET

Table 5.1 User-Defined Descriptor Data (continued)

2-Port USB 2.0 Hub Controller

Datasheet

FIELD

Config Data
Byte 1

Config Data
Byte 2

Non
Removable
Device

Port Disable
Self-Powered

Port Disable
Bus-Powered

Max Power
Self-Powered

Max Power
Bus-Powered

Hub Controller
Max Current
Self-Powered

DEFAULT
BYTE
MSB:

LSB

6 1 88 0C Configuration data byte #1 for Hub options.

7 1 90 90 Configuration data byte #2 for Hub options.

8 1 00 00 Defines the ports that contain attached

9 1 00 00 Selects the ports that will be permanently

A 1 00 00 Selects the ports that will be permanently

B 1 01 01 Max Current for this configuration (expressed

C 1 64 64 Max Current for this configuration (expressed

D 1 01 01 Max Current (expressed in 2mA units).

SIZE

(BYTES)

CFG

SELF

(HEX)

DEFAULT

CFG
BUS

(HEX) DESCRIPTION

devices (this is used only when Hub is part of
a compound device).

disabled

disabled

in 2mA units).

in 2mA units).

Hub Controller
Max Current
Bus-Powered

Power-On
Time

E 1 64 64 Max Current (expressed in 2mA units).

F 1 32 32 Time until power is stable.

5.2.3.1 EEPROM Offset 1:0(h) - Vendor ID

BIT

NUMBER BIT NAME DESCRIPTION

15:8 VID_MSB Most Signifi cant Byte of the Vendor ID.

7:0 VID_LSB Least Significant Byte of the Vendor ID.

5.2.3.2 EEPROM Offset 3:2(h) - Product ID

BIT

NUMBER BIT NAME DESCRIPTION

15:8 PID_MSB Most Significant Byte of the Produ ct ID.

7:0 PID_LSB Least Significant Byte of the Product ID.

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2-Port USB 2.0 Hub Controller

Datasheet

5.2.3.3 EEPROM Offset 5:4(h) - Device ID

BIT

NUMBER BIT NAME DESCRIPTION

15:8 DID_MSB Most Signifi cant Byte of the Device ID.

7:0 DID_LSB Lea st Significant Byte of the Device ID.

5.2.3.4 EEPROM Offset 6(h) - CONFIG_BY TE_1

BIT

NUMBER BIT NAME DESCRIPTION

7 SELF_BUS_PWR Self or Bus Power: Selects between Self- and Bus-Powered operation.

0 = Bus-Powered operation. (BUS Default)
1 = Self-Powered operation. (SELF Default)

Note: If Dynamic Power Switching is enabled, this bit is ign ored and the
SELF_PWR pin is used to determine if the hub is operating from self or bus

power.
6 Reserved Reserved
5 HS_DISABLE High Speed Disable: Disables the capability to attach as either a High/Full-

4 Reserved Reserved
3 EOP_DISABLE EOP Disable: Disables EOP gene ration at EOF1 when no downstream

2:1 CURRENT_SNS Over Current Sense: Indicates wh ether current sensing is ganged.

0 Reserved Reserved

speed device, and forces attachment as Full-speed only i.e. (no High-Speed

support).

0 = High-/Full-Speed. (Default)

1 = Full-Speed-Only (High-Speed disabled!)

directed traffic is in progress.

0 = EOP generation at EOF1 is enabled.

1 = EOP generation at EOF1 is disabled, (normal operation). (Default)

00 = Ganged sensing (all ports together). (Default for self-power)

01 = Reserved

1x = Over current sensing not supported. (may be used with Bus-Powered

configurations only!, and is the default for bus-power)

5.2.3.5 EEPROM Offset 7(h) - CONFIG_BY TE_2

BIT

NUMBER BIT NAME DESCRIPTION

7 DYNAMIC Dynamic Power Enable: Controls the ability for the Hub to transition to Bus-

6 Reserved Reserved

SMSC USB2502 21 Revision 2.3 (08-27-07)

Powered operation if the local power source is removed (can revert back to

Self-Power if local power source is restored).

0 = No Dynamic auto-switching.

1 = Dynamic Auto-switching capable.(Default)

DATASHEET

2-Port USB 2.0 Hub Controller

BIT

NUMBER BIT NAME DESCRIPTION

5:4 OC_TIMER OverCurrent Timer: Over Current Timer delay.

00 = 0.1ms

01 = 2ms (Default)

10 = 4ms

11 = 6 m s
3 COMPOUND Compound Device: De signates if Hub is part of a compound device.

0 = No. (Default)

1 = Yes, Hub is part of a compound device.

2:0 Reserved Reserved.

5.2.3.6 EEPROM Offset 8(h) - Non-Removable Device

BIT

NUMBER BIT NAME DESCRIPTION

7:0 NR_DEVICE Non-Removable Device: Indicates which port(s) include non-removable devic-

es. ‘0’ = port is removable, ‘1’ = port is non-removable.

Bit 7:3= 0; Reserved

Bit 2= 1; Port 2 non-removable.

Bit 1= 1; Port 1 non removable.

Bit 0 is Reserved, always = ‘0’.

Datasheet

5.2.3.7 EEPROM Offset 9(h) - Port Disable For Self Powered Operation

BIT

NUMBER BIT NAME DESCRIPTION

7:0 PORT_DIS_SP Port Disable Self-Powered: Disables 1 or more contiguous ports. ‘0’ = port

is available, ‘1’ = port is disabled.

Bit 7:3= 0; Reserved

Bit 2= 1; Port 2 is disabled.

Bit 1= 1; Port 1 is disabled.

Bit 0 is Reserved, always = ‘0’

5.2.3.8 EEPROM Offset A(h) - Port Disable For Bus Powered Operation

BIT

NUMBER BIT NAME DESCRIPTION

7:0 PORT_DIS_BP Port Disable Bus-Powered: Disables 1 or more contiguous ports. ‘0’ = port

is available, ‘1’ = port is disabled.

Bit 7:3= 0; Reserved

Bit 2= 1; Port 2 is disabled.

Bit 1= 1; Port 1 is disabled.

Bit 0 is Reserved, always = ‘0’

Revision 2.3 (08-27-07) 22 SMSC USB2502

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2-Port USB 2.0 Hub Controller

Datasheet

5.2.3.9 EEPROM Offset B(h) - Max Power For Self Powered Operation

BIT

NUMBER BIT NAME DESCRIPTION

7:0 MAX_PWR_SP Max Power Self_Powered: Value in 2mA increments that the Hub consumes

from an upstream port (VBUS) when operating as a self-powered hub. This
value includes the hub silicon along with the combi ned power consumption
(from VBUS) of all associated circuitry on the board. This value also includes
the power consumption of a permanently attached peripheral if t he hub is
configured as a compound device, and the embedded perip heral reports
0mA in its descriptors.

Note: The USB 2.0 Specification does not permit this value to exceed
100mA

A value of 50 (decimal) indicates 100mA.

5.2.3.10 EEPROM Offset C(h) - Max Power For Bus Powered Operation

BIT

NUMBER BIT NAME DESCRIPTION

7:0 MAX_PWR_BP Max Power Bus_Powered: Value in 2mA increments that the Hub consumes

from an upstream port (VBUS) when operating as a bus-powered hub. This
value includes the hub silicon along with the combi ned power consumption
(from VBUS) of all associated circuitry on the board. This value also includes
the power consumption of a permanently attached peripheral if t he hub is
configured as a compound device, and the embedded perip heral reports
0mA in its descriptors.

A value of 50 (decimal) indicates 100mA.

5.2.3.11 EEPROM Offset D(h) - Hub Controller Max Current For Self Powered Operation

BIT

NUMBER BIT NAME DESCRIPTION

7:0 HC_MAX_C_SP Hub Controller Max Current Self-Powered: Value in 2mA increments that the

Hub consumes from an upstream port (VBUS) when operating as a self­powered hub. This value includes the hub silicon alon g with the combined
power consumption (from VBUS) of all associated circuitry on the board.
This value does NOT include the power consumption of a permanen tly
attached peripheral if the hub is configured as a compound device.

Note: The USB 2.0 Specification does not permit this value to exceed
100mA

A value of 50 (decimal) indicates 100mA, which is the default value.

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2-Port USB 2.0 Hub Controller

Datasheet

5.2.3.12 EEPROM Offset E(h) - Hub Controller Max Current For Bus Powered Operation

BIT

NUMBER BIT NAME DESCRIPTION

7:0 HC_MAX_C_BP Hub Controller Max Current Bus-Powered: Value in 2mA increments that the

Hub consumes from an upstream port (VBUS) when operating as a self­powered hub. This value includes the hub silicon alon g with the combined
power consumption (from VBUS) of all associated circuitry on the board.
This value does NOT include the power consumption of a permanen tly
attached peripheral if the hub is configured as a compound device.

A value of 50 (decimal) indicates 100mA, which is the default value.

5.2.3.13 EEPROM Offset F(h) - Power-On Time

BIT

NUMBER BIT NAME DESCRIPTION

7:0 POWER_ON_TIME Power On Time: The length of time that is takes (in 2 ms intervals) from the

time the host initiated power-on sequence begins on a port until power is
good on that port.

5.3 SMBus Slave Interface

Instead of loading User-Defined Descriptor data from an external EEPROM, the SMSC Hub can be
configured to receive a code load from an external processor via an SMBus interface. The SMBus
interface shares the same pins as the EEPROM interface, if CFG_SEL1 & CFG_SEL0 activates the
SMBus interface, external EEPROM support is no longer available (and the user-defined descriptor
data must be downloaded via the SMBus). Due to system issues, the SMSC Hub waits indefinitely for
the SMBus code load to complete and only “appears” as a newly connecte d device on USB after the
code load is complete.

The Hub’s SMBus implementation is a subset of the SMBus interface to the host. The device is a

slave-only SMBus device. The implementation in the device is a subset of SMBus since it only supports

two protocols.
The Write Byte and Read Byte protocols are the only valid SMBus protocols for the Hub. The Hub

responds to other protocols as described in Section 5.3 .2, "Invalid Protocol Response Behavior," on

page 25. Reference the System Management Bus Specification, Rev 1.0.

The SMBus interface is used to read and write the registers in the device. Th e register set is shown
in Section 5.3.9, "Internal SMBus Memory Register Set," on page 26.

5.3.1 Bus Protocols

Typical Write Byte and Read Byte protocols are shown below. Register accesses are performed using
7-bit slave addressing, an 8-bit register address fiel d, and an 8-bit data field. The shading indicates
the Hub driving data on the SMBDATA line; otherwise, host data is on the SDA/SMBDATA line .

The slave address is the unique SMBus Interface Address for the Hub that identifi es it on SMBus. The
register address field is the internal address of the register to be accessed. The register data field is
the data that the host is attempting to write to the register or the contents of the register that the host
is attempting to read.

Note: Data bytes are t ransferred MSB first (msb first).

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Datasheet

5.3.1.1 Byte Protocols

When using the Hub SMBus Interface for byte transfers, a write will always consist of the SMBus
Interface Slave Address byte, followed by the Internal Add ress Register byte, then the data byte.

The normal read protocol consists of a write to the HUB with the SMBus Interface Address byte,
followed by the Internal Address Register byte. Then restart the Serial Communication with a Read
consisting of the SMBus Interface Address byte, fo llowed by the data byte read from the Hub. This
can be accomplished by using the Read Byte protocol.

Note: For th e following SMBus tables:

Denotes Master-to-Slave Denotes Slave-to-Master

Write B yte
The Write Byte protocol is used to write data to the registers. The data will only be written if the p rotocol

shown in Table 5.2 is performed correctly. Only one byte is transferred at a time for a Write Byte
protocol.

Table 5. 2 SMBus Write Byte Protocol

Field: Start Slave Addr Wr Ack Reg. Addr Ack Reg. Data Ack Stop

Bits:1 71181811

Read Byte
The Read Byte protocol is used to read data from the registers. The data will only be read if the

protocol shown in Table 5.3 is performed correctly. Only one byte is transferred at a time for a Read
Byte protocol.

Table 5.3 SMBus Read Byte Protocol

Field: Start Slave

Addr

Bits: 1 7 1 1 8 1 1 7 1 1 8 1 1

Wr Ack Reg.

Addr

Ack Start Slave

Addr

Rd Ack Reg.

Data

Nack Stop

5.3.2 Invalid Protocol Response Behavior

Registers that are accessed with an invalid protocol are not updated. A register is only updated
following a valid protocol. The only valid protocols are Write Byte and Read Byte, which a re described
above.

The Hub only responds to the hardware selected Slave Address.
Attempting to communicate with the Hub over SMBus wit h an invalid slave address or invalid p rotocol

results in no response, and the SMBus Slave Interface returns to th e idle state.
The only valid registers that are accessible by the SMBus slave address are the registers defined in

the Registers Section. See Section 5.3.3 for the response to undef ined registers.

5.3.3 General Call Address Response

The Hub does not respond to a general call address of 0000_000b.

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5.3.4 Slave Device Time-Out

According to the SMBus Specification, V1.0 devices in a transfer can abort the transfer in progress
and release the bus when any single clock low interval exceeds 25ms (T
have detected this condition must reset their communication and be able to receive a new START
condition no later than 35ms (T

Note: Some simple devices do not contain a clock low drive ci rcuit; t his simple kind of device typi cally

resets its communications port after a start or stop condition.

TIMEOUT, MAX

5.3.5 Stretching the SCLK Signal

The Hub supports stretching of the SCLK by other device s on the SMBus. The Hub does not stretch
the SCLK.

5.3.6 SMBus Timing

The SMBus Slave Interface complies with the SMBus AC Timing Specification. See the SMBus timing
in the “Timing Diagram” section.

5.3.7 Bus Reset Sequence

2-Port USB 2.0 Hub Controller

Datasheet

TIMEOUT, MIN

).

). Devices that

The SMBus Slave Interface resets and returns to the idle state upon a START field followed
immediately by a STOP field.

5.3.8 SMBus Alert Response Address

The SMBALERT# signal is not supported by the Hub.

5.3.9 Internal SMBus Memory Register Set

The following table provides the SMBus slave interface register map value s.

Table 5.4 SMBus Slave Interface Register Map

REG

ADDR R/W REGISTER NAME ABBR

00h R/W Status/Command STCD 7 6 5 4 3 2 1 0
01h R/W VID LSB VIDL 7 6 5 4 3 2 1 0
02hR/WVID MSB VIDM7 6543210
03h R/W PID LSB PIDL 7 6 5 4 3 2 1 0
04hR/WPID MSB PIDM7 6543210
05hR/WDID LSB DIDL76543210
06h R/W DID MSB DIDM 7 6 5 4 3 2 1 0

BIT 7

(MSB) BIT 6 BIT 5 BIT 4 BIT 3 BIT 2 BIT 1

BIT 0
(LSB)

07h R/W Config Data Byte 1 CFG1 7 6 5 4 3 2 1 0
08h R/W Config Data Byte 2 CFG2 7 6 5 4 3 2 1 0
09h R/W Non-Removable

Devices
0Ah R/W Port Disable (Self) PDS 7 6 5 4 3 2 1 0
0Bh R/W Port Disable (Bus) PDB 7 6 5 4 3 2 1 0

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Datasheet

Table 5.4 SMBus Slave Interface Register Map (continued)

REG

ADDR R/W REGISTER NAME ABBR

BIT 7

(MSB) BIT 6 BIT 5 BIT 4 BIT 3 BIT 2 BIT 1

0Ch R/W Max Power (Self) MAXPS 7 6 5 4 3 2 1 0
0Dh R/W Max Power (Bus) MAXPB 7 6 5 4 3 2 1 0
0Eh R/W Hub Controller

HCMCS 7 6 5 4 3 2 1 0

Max Current (Self)
0Fh R/W Hub Controller

HCMCB 7 6 5 4 3 2 1 0

Max Current (bus)
10h R/W Power-on Time PWRT 7 6 5 4 3 2 1 0

5.3.9.1 Register 00h: Status/Command (Reset = 0x00)

BIT

NUMBER BIT NAME DESCRIPTION

7:3 Reserved Reserved. {Note: Software must never write a ‘1’ t o these bits}

2 RESET Reset the SMBus Interface and internal memory back to RESET_N assertion

default settings. {Note: During this reset, this b it is automatically cleared to
its default value of 0.}

0 = Normal Run/Idle State.
1 = Force a reset.

BIT 0
(LSB)

1 WRITE_PROT Write Protect: The external SMBus host sets this bit after the Hub’s internal

memory is loaded with configuration data. {Note: The Ext ernal SMBus Host
is responsible for verification of downloaded data.}

0 = The internal memory (address range 01-10h) is no t write protected.
1 = The internal memory (address range 01-10h) is “write-pro tected” to
prevent unintentional data corruption.}

{Note: This bit is write once and is only cleared by assertion of the external
RESET_N pin.}

0 USB_ATTACH USB Attach & power-down the SMBus Interface.

0 = Default; SMBus slave interface is active.
1 = Hub will signal a USB attach event to an upstream device, Note: SMBus
Slave interface will completely power down after the ACK has completed.

{Note: This bit is write once and is only cleared by assertion of the external
RESET_N pin.}

5.3.9.2 Register 01h: Vendor ID (LSB) (Reset = 0x00)

BIT

NUMBER BIT NAME DESCRIPTION

7:0 VID_LSB Least Significant Byte of the Vendor ID.

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5.3.9.3 Register 02h: Vendor ID (MSB) (Reset = 0x00)

BIT

NUMBER BIT NAME DESCRIPTION

7:0 VID_MSB Most Significant Byte of the Vendor ID.

5.3.9.4 Register 03h: Product ID (LSB) (Reset = 0x00)

BIT

NUMBER BIT NAME DESCRIPTION

7:0 PID_LSB Least Significant Byte of the Product ID.

5.3.9.5 Register 04h: Product ID (MSB) (Reset = 0x00)

BIT

NUMBER BIT NAME DESCRIPTION

7:0 PID_MSB Most Significant Byte of the Product ID.

2-Port USB 2.0 Hub Controller

Datasheet

5.3.9.6 Register 05h: Device ID (LSB) (Reset = 0x00)

BIT

NUMBER BIT NAME DESCRIPTION

7:0 DID_LSB Lea st Significant Byte of the Device ID.

5.3.9.7 Register 06h: Device ID (MSB) (Reset = 0x00)

BIT

NUMBER BIT NAME DESCRIPTION

7:0 DI D_MSB Most Significant Byte of the Device ID.

5.3.9.8 Register 07h: CONFIG_BYTE_1 (Reset = 0x00)

BIT

NUMBER BIT NAME DESCRIPTION

7 SELF_BUS_PWR Self or Bus Power: Selects between Self- and Bus-Powered operation.

0 = Bus-Powered operation.
1 = Self-Powered operation.

Note: If Dynamic Power Switching is enabled, this bit is ign ored and the
SELF_PWR pin is used to determine if the hub is operating from self or bus
power.

6 Reserved Reserved

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Datasheet

BIT

NUMBER BIT NAME DESCRIPTION

5 HS_DISABLE High Speed Disable: Disables the capability to attach as either a High/Full-

4 Reserved Reserved
3 EOP_DISABLE EOP Disable: Disables EOP generation of EOF1 when in Full-Speed mode.

2:1 CURRENT_SNS Over Current Sense: Indicates wh ether current sensing isganged.

0 Reserved Reserved

speed device, and forces attachment as Full-speed only i.e. (no High-Speed
support).

0 = High-/Full-Speed.
1 = Full-Speed-Only (High-Speed disabled!)

0 = EOP generation is normal.
1 = EOP generation is disabled.

00 = Ganged sensing (all ports together).
01 = Reserved1x = Over current sensing not supported. (must only be used
with Bus-Powered configurations!)

5.3.9.9 Register 08h: Configuration Data Byte 2 (Reset = 0x00)

BIT

NUMBER BIT NAME DESCRIPTION

7 DYNAMIC Dynamic Power Enable: Controls the ability for the Hub to transition to Bus-

Powered operation if the local power source is removed (can revert back to
Self-Power if local power source is restored).

0 = No Dynamic auto-switching.
1 = Dynamic Auto-switching capable.

6 Reserved Reserved

5:4 OC_TIMER OverCurrent Timer: Over Current Timer delay.

00 = 0.1ms
01 = 2ms
10 = 4ms
11 = 6 m s

3 COMPOUND Compound Device: De signates if Hub is part of a compound device.

0 = No.
1 = Yes, Hub is part of a compound device.

2:0 Reserved Reserved

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2-Port USB 2.0 Hub Controller

5.3.9.10 Register 09h: Non-Removable Device (Reset = 0x00)

BIT

NUMBER BIT NAME DESCRIPTION

7:0 NR_DEVICE Non-Removable Device: Indicates which port(s) include non-removable devic-

es. ‘0’ = port is removable, ‘1’ = port is non-removable.
Bit 7:3: Reserved, always = ‘0’

Bit 2= 1; Port 2 non-removable.
Bit 1= 1; Port 1 non removable.
Bit 0 is Reserved, always = ‘0’.

5.3.9.11 Register 0Ah: Port Disable For Self Powered Operation (Reset = 0x00)

BIT

NUMBER BIT NAME DESCRIPTION

Datasheet

7:0 PORT_DIS_SP Port Disable Self-Powered: Disables 1 or more contiguous ports. ‘0’ = port

is available, ‘1’ = port is disabled.
Bit 7:3= 0; ReservedBit 2= 1; Port 2 is disabled.

Bit 1= 1; Port 1 is disabled.
Bit 0 is Reserved, always = ‘0’

5.3.9.12 Register 0Bh: Port Disable For Bus Powered Operation (Reset = 0x00)

BIT

NUMBER BIT NAME DESCRIPTION

7:0 PORT_DIS_BP Port Disable Bus-Powered: Disables 1 or more contiguous ports. ‘0’ = port

is available, ‘1’ = port is disabled.
Bit 7:3= 0; ReservedBit 2= 1; Port 2 is disabled.

Bit 1= 1; Port 1 is disabled.
Bit 0 is Reserved, always = ‘0’

5.3.9.13 Register 0Ch: Max Power For Self Powered Operation (Reset = 0x00)

BIT

NUMBER BIT NAME DESCRIPTION

7:0 MAX_PWR_SP Max Power Self_Powered: Value in 2mA increments that the Hub consumes

from an upstream port (VBUS) when operating as a self-powered hub. This
value includes the hub silicon along with the combi ned power consumption
(from VBUS) of all associated circuitry on the board. This value also includes
the power consumption of a permanently attached peripheral if t he hub is
configured as a compound device, and the embedded perip heral reports
0mA in its descriptors.

Note: The USB 2.0 Specification does not permit this value to exceed
100mA

A value of 50 (decimal) indicates 100mA.

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Datasheet

5.3.9.14 Register 0Dh: Max Power For Bus Powered Operation (Reset = 0x00)

BIT

NUMBER BIT NAME DESCRIPTION

7:0 MAX_PWR_BP Max Power Bus_Powered: Value in 2mA increments that the Hub consumes

from an upstream port (VBUS) when operating as a bus-powered hub. This
value includes the hub silicon along with the combi ned power consumption
(from VBUS) of all associated circuitry on the board. This value also includes
the power consumption of a permanently attached peripheral if t he hub is
configured as a compound device, and the embedded perip heral reports
0mA in its descriptors.

A value of 50 (decimal) indicates 100mA.

5.3.9.15 Register 0Eh: Hub Controller Max Current For Self Powered Operation (Reset = 0x00)

BIT

NUMBER BIT NAME DESCRIPTION

7:0 HC_MAX_C_SP Hub Controller Max Current Self-Powered: Value in 2mA increments that the

Hub consumes from an upstream port (VBUS) when operating as a self­powered hub. This value includes the hub silicon alon g with the combined
power consumption (from VBUS) of all associated circuitry on the board.
This value does NOT include the power consumption of a permanen tly
attached peripheral if the hub is configured as a compound device.

Note: The USB 2.0 Specification does not permit this value to exceed
100mA

A value of 50 (decimal) indicates 100mA, which is the default value.

5.3.9.16 Register 0Fh: Hub Controller Max Current For Bus Powered Operation (Reset = 0x00)

BIT

NUMBER BIT NAME DESCRIPTION

7:0 HC_MAX_C_BP Hub Controller Max Current Bus-Powered: Value in 2mA increments that the

Hub consumes from an upstream port (VBUS) when operating as a bus­powered hub. This value will include the hub silicon along with the combined
power consumption (from VBUS) of all associated circuitry on the board.
This value will NOT include the power consumption of a p ermanently
attached peripheral if the hub is configured as a compound device.

A value of 50 (decimal) would indicate 100mA, which is the def ault value.

5.3.9.17 Register 10h: Power-On Time (Reset = 0x00)

BIT

NUMBER BIT NAME DESCRIPTION

7:0 POWER_ON_TIME Power On Time: The length of time that it takes (in 2 ms intervals) from the

time the host initiated power-on sequence begins on a port until power is
good on that port.

5.3.9.18 Undefined Registers

The registers shown in Table 5.4 a re the defined registers in the Hub. Reads to undefined registers
return 00h. Writes to undefined registers have no effect and do not return an error.

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DATASHEET

5.3.9.19 Reserved Registers

Unless otherwise instructed, only a ‘0’ may be written to all rese rved registers or bits.

5.4 Default Configuration Option:

The SMSC Hub can be configured via its internal default configurat ion. (please see for specific details
on how to enable default configuration.

Please refer to Table 5.1 on page 1 9 for the internal default values that are loaded when this option is
selected.

5.5 Default Strapping Options:

The SMSC Hub can be configured via a combination of int ernal default values and pin strap options.
Please see Table 4.1, "7-Port Hub Pin Descriptions" for specific details on how to enable the
default/pin-strap configuration option.

The strapping option pins only cover a limited sub- set of the configuration o ptions. The internal def ault
values will be used for the bits & registers that are not controlled by a strapping option pin. Please
refer to Table 5.1 on page 19 for the internal default values that are loaded when this option is selected.

2-Port USB 2.0 Hub Controller

Datasheet

The Green LED pins are sampled after RESET_N negation, and the logic values are used to config ure
the hub if the internal default config uration mode is selected. The implementation shown below (see

Figure 5.1) shows a recommended passive scheme. When a pin is configured with a “Strap High”

configuration, the LED functions with active low signalling, and the PAD will “sink” the current from the
external supply. When a pin is configured with a “Strap Low” configuration, the LED functions with
active high signalling, and the PAD will “source” the current to the external LED.

+V

Strap High

50K

GR1

HUB

GR2

Strap Low

50K

Figure 5.1 LED Strapping Option

5.6 Reset

There are two different resets that the Hub experiences. One is a hardware reset (via the RESET_N
pin) and the second is a USB Bus Reset.

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Datasheet

5.6.1 External Hardware RESET_N

A valid hardware reset is defined as, assertion of RESET_N for a minimum of 1us after all power
supplies are within operating range. While reset is asserted, the Hub (and its associated external
circuitry) consumes less than 500
Hub and 200

μA for the external circuitry).

Assertion of RESET_N (external pin) causes the following:

1. All downstream ports are disabled, and PRTPWR power to downstream devices is removed.

2. The PHYs are disabled, and the differential pairs will be in a high-impedance state.

3. All transactions immediately terminate; no states are saved.

4. All internal registers return to the default state (in most cases, 00(h)).

5. The external crystal oscillator is halted.

6. The PLL is halted.

7. LED indicators are disabled.

μA of current from the upstream USB power source (300μA for the

The Hub is “operational” 500

μs after RESET_N is negated.

Once operational, the Hub immediately reads OEM-specific data from the external EEPROM (if the
SMBus option is not disabled).

5.6.1.1 RESET_N for Strapping Option Configuration

RESET_N

VSS

Strap Pins

VSS

Hardware

reset

asserted

Don’t Care

Read Strap

Options

t1

t2

Valid

Drive Strap

Outputs to

inactive

levels

t5 t6

t3

t4

Don’t Care

Attach

USB

Upstream

USB Reset

recovery

Idle

t7 t8

Driven by Hub if strap is an output.

Start

completion

request

response

Figure 5.2 Reset_N Timing for Default/Strap Option Mode

T able 5.5 Reset_N Timing for Default/Strap Option Mode

NAME DESCRIPTION MIN TYP MAX UNITS

t1 RESET_N Asserted. 1 μsec
t2 Strap Setup Time 16.7 nsec
t3 Strap Hold Time. 16.7 1400 nsec
t4 hub outputs driven to inactive logic states 2.0 1.5

μsec

t5 USB Attach (See Note). 100 msec

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Datasheet

Table 5.5 Reset_N Timing for Default/Strap Option Mode (continued)

NAME DESCRIPTION MIN TYP MAX UNITS

t6 Host acknowl edges attach and signals USB

100 msec

Reset.
t7 USB Idl e. undefined msec
t8 Completio n t ime for requ ests (with or wit hout d ata

5msec

stage).

Notes:

 When in Bus-Powered mode, the Hub and its associated circuitry mu st not consume more than

100mA from the upstream USB power source during t1+t5.

 All Power Supplies must have reached th e operating levels mandated in Secti on Chapter 7, "DC

Parameters", prior to (or coincident with) the assertion of RESET_N.

5.6.1.2 RESET_N for EEPROM Configuration

Hardware

reset

asserted

Read Strap

Options

Read EEPROM

+

Set Options

Attach

USB

Upstream

USB Reset

recovery

Idle

Start

completion

request

response

t4

t1

t2

t3

t5 t6 t7

RESET_N

VSS

Figure 5.3 Reset_N Timing for EEPROM Mode

Table 5.6 Reset_N Timing for EEPROM Mode

NAME DESCRIPTION MIN TYP MAX UNITS

t1 RESET_N Asserted. 1 μsec
t2 Hub Recovery/Stabilization. 500

μsec

t3 EEPROM Read / Hub Config. 2.0 99.5 msec
t4 USB Attach (See Note). 100 msec
t5 Host acknowl edges attach and signals USB

100 msec

Reset.
t6 USB Idl e. undefined msec
t7 Completio n t ime for requ ests (with or wit hout d ata

5msec

stage).

Notes:

 When in Bus-Powered mode, the Hub and its associated circuitry mu st not consume more than

100mA from the upstream USB power source during t4+t5+t6+t7.

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Datasheet

 All Power Supplies must have reached th e operating levels mandated in Secti on Chapter 7, "DC

Parameters", prior to (or coincident with) the assertion of RESET_N.

5.6.1.3 RESET_N for SMBus Slave Configuration

Start

completion

request

response

RESET_N

VSS

Hardware

reset

asserted

Reset

Negation

t1

SMBus Code

Load

t2 t4

Hub PHY

Stabilization

t3

Attach

USB

Upstream

USB Reset

recovery

t5

Idle

t6 t7

Figure 5.4 Reset_N Timing for SMBus Mode

T able 5.7 Reset_N T iming for SMBus Mode

NAME DESCRIPTION MIN TYP MAX UNITS

t1 RESET_N Asserted. 1 μsec
t2 Hub Recove ry/Stabilization. 500

μsec

t3 SMBus Code Load (Se e Note). 10 99.5 msec
t4 Hub Confi guration and USB Attach. 100 msec
t5 Host ackn owledges attach and signals USB

100 msec

Reset.
t6 USB Idle. Undefined msec
t7 Completion time for requests (with or without data

5msec

stage).

Notes:

 For Bus-Powered configurations, the 9 9.5ms (MAX) is required, and the Hub and its associated

circuitry must not consume more than 100mA f rom the upstream USB power source during
t2+t3+t4+t5+t6+t7. For Self-Powered configurations, t 3 MAX is not applicable and the ti me to load
the configuration is determined by the external SMBus host.

 All Power Supplies must have reached th e operating levels mandated in Secti on Chapter 7, "DC

Parameters", prior to (or coincident with) the assertion of RESET_N.

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5.6.2 USB Bus Reset

In response to the upstream port signaling a reset to t he Hub, the Hub does the following:

Note: The Hu b does not propagate the upstream USB reset to downstream devices.

1. Sets default address to 0.

2. Sets configuration to: Unconfigured.

3. Negates PRTPWR to all downstream ports.

4. Clears all TT buffers.

5. Moves device from suspended to active (if suspended).

6. Complies with Section 11.10 of the USB 2.0 Specification for behavior after completion of the reset
sequence.

The Host then configures the Hub and the Hub’s downstream port devices in accordance wi th the USB
Specification.

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Datasheet

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Datasheet

Chapter 6 XNOR Test

XNOR continuity tests all signal pins on the Hub (every pin except for NC, XTAL1/CLKIN, XTAL2,
ATEST/REG_EN, RBIAS, TEST, Power, and Ground). This functionality is enabled by drivi ng TEST
and CFG_SEL[1] high, driving SCLK low and transition RESET_N from low to high . The output from
the XNOR chain is driven to GR2 . For each pin tested for co ntinuity GR2 should toggle.

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2-Port USB 2.0 Hub Controller

Chapter 7 DC Parameters

7.1 Maximum Guaranteed Ratings

PARAMETER SYMBOL MIN MAX UNITS COMMENTS

Datasheet

Storage

Temperature

Lead

Temperature

1.8V supply
voltage

3.3V supply
voltage

Voltage on any

I/O pin

Voltage on

XTAL1

Voltage on

XTAL2

Note: Stresses above the specified parameters could cause permanent damag e to the device. This

T

A

V

DDA18PLL

V

DD18

V

DDA33

V

DDA33PLL

V

DD33CR

is a stress rating only and functional operation of the device at any condition above those
indicated in the operation sections of this specification is not implied. When powering this
device from laboratory or system power supplies, it is important that the Absolute Maximum
Ratings not be exceeded or device failure can result. Some power supplies exhibit voltage
spikes on their outputs when the AC power is switched on or off. In addition, voltage transients
on the AC power line may appear on the DC output. When t his possibi lity exists, it is sugg ested
that a clamp circuit be used.

-55 150 °C

325 °C Soldering < 10 seconds

-0.3 2.5 V

-0.3 4.0 V

-0.3 (3.3V supply voltage + 2)

-0.3 4.0 V

-0.3 V

+ 0.3V V

DD18

≤ 6V

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Datasheet

7.2 Recommended Operating Conditions

PARAMETER SYMBOL MIN MAX UNITS COMMENTS

Operating

Temperature

1.8V supply voltage V

3.3V supply voltage V

T

A

DDA18PLL

V

DD18

DDA33

V

DDA33PLL

V

DD33CR

070°C

1.62 1.98 V

3.0 3.6 V

Voltage on any I/O pin -0.3 5.5 V If any 3.3V supply voltage drops

below 3.0V, then the MAX
becomes:

(3.3V supply voltage + 0.5)
Voltage on XTAL1 -0.3 V
Voltage on XTAL2 -0.3 V

DDA33

DD18

V
V

Table 7.1 DC Electrical Characteristics

PARAMETER SYMBOL MIN TYP MAX UNITS COMMENTS

I, IS Type Input Buffer
Low Input Level

V

ILI

0.8

V

TTL Levels
High Input Level
Input Leakage
Hysteresis (‘IS’ Only)

Input Buffer with Pull-Up
(IPU)

Low Input Level
High Input Level
Low Input Leakage
High Input Leakage

Input Buffer with Pull-Down
IPD

Low Input Level
High Input Level
Low Input Leakage
High Input Leakage

V

V

IHI

I

IL

HYSI

V

ILI

V

IHI

I

ILL

I

IHL

V

ILI

V

IHI

I

ILL

I

IHL

2.0

-10

250 300

2.0
+5

-10

2.0

+10

-80

+10
350

0.8

+45
+10

0.8

-10

-160

V

uA

mV

V

V
uA
uA

V

V
uA
uA

= 0 to V

V

IN

TTL Levels

= 0

V

IN

= V

V

IN

DD33

TTL Levels

= 0

V

IN

= V

V

IN

DD33

DD33

CR

CR

CR

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2-Port USB 2.0 Hub Controller

T able 7.1 DC Electrical Characteristics (continued)

PARAMETER SYMBOL MIN TYP MAX UNITS COMMENTS

ICLK Input Buffer

Datasheet

Low Input Level
High Input Level
Input Leakage
Hysteresis

O8 and I/O8 Type Buffer
Low Output Level
High Output Level
Output Leakage

I/OSD12 Type Buffer
Low Output Level
Output Leakage
Hysteresis

IO-U
(Note 2)

V

V

V

HYSC

V
V

V

V

ILCK

IHCK

I

IL

OL

OH

I

OL

OL

I

OL

HYSI

2.0

-10
50

2.4

-10

-10

250 300

0.8

+10
100

0.4

+10

0.4
+10
350

V
V

uA

mV

V
V

uA

V

µA

mV

TTL Levels

= 0 to V

V

IN

I

= 8 mA @ V

OL

I

= -4mA @ V

OH

= 0 to V

V

IN

(Note 1)

= 12 mA @ V

I

OL

V

= 0 to V

IN

(Note 1)

DD33

DD33

DD33

CR

DD33

DD33

CR

DD33

CR

CR = 3.3V

CR = 3.3V

CR = 3.3V

I-R
(Note 3)

Supply Current Unconfig­ured

High-Speed Host
Full-Speed Host

Supply Current
Configured
(High-Speed Host)

2 Ports @ FS/LS
2 Ports @ HS
1 Port HS, 1 Port FS/LS

Supply Current
Configured
(Full-Speed Host)

1 Port
2 Ports

I

CCINIT

I

CCINIT

I

HCC2

I

HCH2

I

HCH1C1

I

FCC1

I

FCC2

73
65

120
170
140

90
90

mA
mA

Total from all supplies

mA
mA
mA

Total from all supplies

mA
mA

Revision 2.3 (08-27-07) 40 SMSC USB2502

DATASHEET

2-Port USB 2.0 Hub Controller

Datasheet

PARAMETER SYMBOL MIN TYP MAX UNITS COMMENTS

T able 7.1 DC Electrical Characteristics (continued)

Supply Current

I

CSBY

320 425 uA Total from all supplies.

Suspend
Supply Current

I

RST

160 300 uA Total from all supplies.

Reset

Notes:

1. Output leakage is measured with the current pins in high impedance.

2. See USB 2.0 Specification for USB DC electrical characteristics.

3. RBIAS is a 3.3V tolerant analog pin.

CAPACITANCE TA = 25°C; fc = 1MHz; V

DD33CR

= 3.3V

LIMITS

PARAMETER SYMBOL MIN TYP MAX UNIT TEST CONDITION

Clock Input
Capacitance

Input Capacitance C
Output Capacitance C

C

OUT

IN

IN

12 pF All pins except USB pins (and pins under

test tied to AC ground)

8pF

12 pF

Power Sequencing

There are no power supply sequence restrictions for the Hub. The order in which power supplies
power-up and power-down is implementation dependent.

SMSC USB2502 41 Revision 2.3 (08-27-07)

DATASHEET

Chapter 8 AC Specifications

8.1 Oscillator/Clock

Crystal: Pa rallel Resonant, Fundamental Mode, 24 MHz ±100ppm.

2-Port USB 2.0 Hub Controller

Datasheet

External Clock: 50% Duty cycle

8.1.1 SMBus Interface:

The SMSC Hub conforms to all voltage, power, and timing characteristics and specifications as set
forth in the SMBus 1.0 Specification for Slave-Only devices (except as noted in Section 5.3).

8.1.2 I2C EEPROM:

Frequency is fixed at 59KHz ± 20%.

8.1.3 USB 2.0

The Hub conforms to all voltage, power, and timing characteristics and specif ications as set forth in
the USB 2.0 Specification. Please refer to the USB Specification for more information.

± 10%, 24 MHz ± 100ppm, Jit ter < 100ps rms.

Revision 2.3 (08-27-07) 42 SMSC USB2502

DATASHEET

Revision 2.3 (08-27-07) 43 SMSC USB2502

Chapter 9 Package Outlines

D

3

TERMINAL #1

IDENTIFIER AREA

(D1/2 X E1/2)

D1

2-Port USB 2.0 Hub Controller

Datasheet

REVISION HISTORY

D2

e

TERMINA L #1
IDENTIFI ER AREA
(D/2 X E/2)

3

-

DESCRIPTIONREVISION RELEASED BYDATE

SEE SPEC F R O N T PAGE FOR REVISION HISTORY

--

DATASHEET

E2EE1

0.6(MAX)

CHAMFERED CORNERS
ARE OPTIONAL 4X

0.6(MAX)

TOP VIEW

36X 0.2 MIN

BOTTOM VIEW

4X 0°-12°

C

A2

ccc C

4

A1

A

A3

SIDE VIEW

3-D VIEWS

NOTES:

1. ALL DIMENSIONS ARE IN MILLIMETER.

2. POSITION TOLERANCE OF EACH TERMINAL IS ± 0.05mm AT MAXIMUM MATERIAL CONDITION. DIMENSIONS
"b" APPLIES TO P LATED TERMINAL S AND IT IS MEASURED B E TWEEN 0.15 A ND 0. 30 mm FROM THE
TERMINAL TIP.

3. DETAILS OF TERMINAL #1 IDENTIFIER ARE OPTIONAL BUT MUST BE LOCATED WITHIN THE AREA INDICATED.

4. COPLANARITY ZONE APPLIES TO EXPOSED PAD AND TERMINALS.

36X b

2

DECIMAL
X.X
X.XX
X.XXX

MATERIAL

FINISH

EXPOSED PAD

36X L

UNLESS OTHERWISE SPECIFIED
DIMENSIONS ARE IN MILLIMETERS
AND TOLERANCES ARE:

DIM A ND TOL PE R ASME Y14.5M - 1994

ANGULAR
±0.1
±0.05
±0.025

-

-

PRIN T WITH " SCALE TO FIT"
DO NOT SCALE DRAWING

±1°

4

THIRD ANGLE PROJECTI ON

DRAWN

S.K.ILIEV

CHECKED

S.K.ILIEV

APPROVED

S.K.ILIEV

D2 / E2 VARIATIONS

80 ARKAY DRIVE
HAUPPAUGE, NY 11788
USA

NAME

TITLE

DATE

36 TERMINAL QFN, 6x6mm BODY, 0.5mm PITCH

12/6/04

DWG NUMBER

12/6/04 F

SCALE

12/6/04 1:1

PACKAGE OU TLINE

MO-36-QFN-6x6

STD COMPLIANCE

JEDEC: MO-220 1 OF 1

CATALOG PART

REV

SHEET

Figure 9.1 36 Pin QFN Packag e

2-Port USB 2.0 Hub Controller

Figure 9.2 48 Pin TQFP Package Outl ine (7x7x1.4 mm body, 2mm Footprint)

Datasheet

Table 9.1 48 Pin TQFP Package

MIN NOMINAL MAX REMARKS

A ~ ~ 1.60 Overall Package Height
A1 0.05 ~ 0.15 Standoff
A2 1.35 ~ 1.45 Body Thickness

D 8.80 ~ 9.20 X Span

D1 6.90 ~ 7.10 X body Size

E 8.80 ~ 9.20 Y Span
E1 6.90 ~ 7.10 Y body Size

H 0.09 ~ 0.20 Lead Frame Thickness

L 0.45 0.60 0.75 Lead Foot Length
L1 ~ 1.00 ~ Lead Length

e

o

θ

0

0.50 Basic Lead Pitch
~7

o

Lead Foot Angle

W 0.17 0.22 0.27 Lead Width
R1 0.08 ~ ~ Lead Shoulder Radius
R2 0.08 ~ 0.20 Lead Foot Radius

ccc ~ ~ 0.08 Coplanarity

Notes:

1. Controlling Unit: millimeter.

2. Tolerance on the true position of the leads is ± 0.04 mm maximum.

3. Package body dimensions D1 and E1 do not include the mold protrusion.
Maximum mold protrusion is 0.25 mm.

4. Dimension for foot length L measured at the gauge plane 0.25 mm above t he seating plane.

5.

Details of pin 1 identifier are optional but must be located within the zone indicated.

Revision 2.3 (08-27-07) 44 SMSC USB2502

DATASHEET