SMSC USB2512A User Manual

USB2512A

USB 2.0 Hi-Speed 2-Port
Hub Controller

PRODUCT FEATURES

General Description

The SMSC 2-Port Hub is a low power, OEM
configurable, STT (Single transaction translator) hub
controller IC with 2 downstream ports for embedded
USB solutions. The 2-port hub is fully compliant with the
USB 2.0 Specification and will attach to an upstream
port as a Full-Speed Hub or as a Full-/Hi-Speed Hub.
The 2-Port Hub supports Low-Speed, Full- Speed, and
Hi-Speed (if operating as a Hi-Speed Hub) downstream
devices on all of the enabled downstream ports.

General Features

 Hu b Controller IC with 2 downstream ports
 Enh anced OEM configuration options available

through either a single serial I
SMBus Slave Port

 3 6-pin (6x6mm) QFN lead-free, RoHS compliant

package

Hardware Features

 L ow power operation
 Full Power Management with individual or ganged

power control of each downstream port

 On-chip Power On Reset (POR)
 Interna l 1.8V Voltage Regulator
 Full y integrated USB termination and Pull-up/Pull-

down resistors

 On Boa rd 24MHz Crystal Driver, Resonator or

External 24MHz cloc k input

 Enh anced EMI rejection and ESD protection

performance

OEM Selectable Features

 Cu stomizable Vendor ID, Product ID, and Device ID
 Select whether the hub is part of a compound device

(When any downstream port is permanently
hardwired to a USB peripheral device, the hub is part
of a compound device)

 Flexib le port mapping and disable sequence. Ports

can be disabled/reordered in any order to support
multiple product SKUs. Hub will automatically reorder
the remaining ports to match the Host controller's
numbering scheme.

 Prog rammable USB differential-pair pin location.

Ease PCB layout by aligning USB signal lines directly
to connectors

 Prog rammable USB signal drive strength. Recover

USB signal integrity due to compromised system
environment using 2-level driving strength resolution

2

C EEPROM, or

Datasheet

 Select the presence of a permanently hardwired USB

peripheral device on a port by port basis

 C onfigure the delay time for filtering the over-current

sense inputs

 C onfigure the delay time for turning on downstream

port power

 Indicate the maximum current that the 2-port hub

consumes from the USB upstream port

 Ind icate the maximum current required for the hub

controller

 Pi n Selectable Options for Default Configuration

— Select Downstream Ports as Non-Removable Ports

Applications

 L CD monitors and TVs
 Multi-function USB peripherals
 PC mo ther boards
 Set-top b oxes, DVD players, DVR/PVR
 Prin ters and scanners
 PC me dia drive bay
 Po rtable hub boxes
 Mobile PC docking
 Embedded systems

SMSC USB2512A DATASHEET Revision 1.96 (07-11-08)

USB 2.0 Hi-Speed 2-Port Hub Controller

ORDER NUMBERS:

USB2512A-AEZG FOR 36 PIN, QFN LEAD-FREE ROHS COMPLIANT PACKAGE

Datasheet

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

Copyright © 2008 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 1.96 (07-11-08) 2 SMSC USB2512A

DATASHEET

USB 2.0 Hi-Speed 2-Port Hub Controller

Datasheet

Table of Contents

Chapter 1 Pin Configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

Chapter 2 Block Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

Chapter 3 Pin Descriptions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

3.1 PIN Descriptions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

3.2 Buffer Type Descriptions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

Chapter 4 Configuration Options. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

4.1 2-Port Hub . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

4.1.1 Hub Configuration Options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

4.1.2 VBus Detect. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

4.2 EEPROM Interface. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

4.2.1 Internal Register Set (Common to EEPROM and SMBus) . . . . . . . . . . . . . . . . . . . . . . . 13

4.2.2 I

4.2.3 In-Circuit EEPROM Programming. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25

4.3 SMBus Slave Interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25

4.3.1 Bus Protocols . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25

4.3.2 Invalid Protocol Response Behavior . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26

4.3.3 General Call Address Response . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26

4.3.4 Slave Device Time-Out . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26

4.3.5 Stretching the SCLK Signal. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27

4.3.6 SMBus Timing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27

4.3.7 Bus Reset Sequence. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27

4.3.8 SMBus Alert Response Address. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27

4.4 Default Configuration Option: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27

4.5 Default Strapping Options: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27

4.6 Reset . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27

4.6.1 Internal POR Hardware Reset. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27

4.6.2 External Hardware RESET_N . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28

4.6.3 USB Bus Reset . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30

2

C EEPROM. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24

Chapter 5 DC Parameters. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32

5.1 Maximum Guaranteed Ratings. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32

5.2 Operating Conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33

Chapter 6 AC Specifications. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36

6.1 Oscillator/Clock. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36

6.1.1 SMBus Interface:. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36

6.1.2 I

6.1.3 USB 2.0 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36

2

C EEPROM: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36

Chapter 7 Package Outline . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37

SMSC USB2512A 3 Revision 1.96 (07-11-08)

DATASHEET

USB 2.0 Hi-Speed 2-Port Hub Controller

Datasheet

List of Figures

Figure 1.1 USB2512A 36-Pin QFN (Embedded Footprint) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

Figure 2.1 USB2512A Block Diagram. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

Figure 4.1 Block Write. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26

Figure 4.2 Block Read. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26

Figure 4.3 Reset_N Timing for Default/Strap Option Mode. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28

Figure 4.4 Reset_N Timing for EEPROM Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29

Figure 4.5 Reset_N Timing for SMBus Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30

Figure 5.1 Supply Rise Time Model . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32

Figure 6.1 Typical Crystal Circuit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36

Figure 6.2 Formula to find value of C1 and C2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36

Figure 7.1 36-Pin QFN, 6x6mm Body, 0.5mm Pitch . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37

Revision 1.96 (07-11-08) 4 SMSC USB2512A

DATASHEET

USB 2.0 Hi-Speed 2-Port Hub Controller

Datasheet

List of Tables

Table 3.1 USB2512A Pin Descriptions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

Table 3.2 SMBus or EEPROM Interface Behavior . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

Table 3.3 USB2512A Power, Ground, and No Connect . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

Table 3.4 USB2512A Buffer Type Descriptions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

Table 4.1 Internal Default, EEPROM and SMBus Register Memory Map. . . . . . . . . . . . . . . . . . . . . . . . 13

Table 4.2 Port Remap Register for Ports 1 & 2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23

Table 4.3 Reset_N Timing for Default/Strap Option Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28

Table 4.4 Reset_N Timing for EEPROM Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29

Table 4.5 Reset_N Timing for SMBus Mode. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30

Table 5.1 DC Electrical Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33

Table 5.2 Pin Capacitance. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35

SMSC USB2512A 5 Revision 1.96 (07-11-08)

DATASHEET

Chapter 1 Pin Configuration

USB 2.0 Hi-Speed 2-Port Hub Controller

Datasheet

SUSP_IND/LOCAL_PWR/NON_REM0

VDDA33

USBUP_DM

USBUP_DP

XTAL2

XTAL1/CLKIN

VDD18PLL

RBIAS

VDD33PLL

RESET_N24HS_IND/CFG_SEL123SCL/SMBCLK/CFG_SEL0

VBUS_DET

26

25

27

28
29
30
31
32

Embedded Footprint

33

(Top View QFN-36)

34
35

(must be connected to VSS)

36

1

USBDN1_DM

SMSC

USB2512A

Thermal Slug

2

3

USBDN1_DP

USBDN2_DM

4

USBDN2_DP

VDD33

SDA/SMBDATA/NON_REM121NC20NC

22

5NC6NC7NC8NC9

VDDA33

NC

19

18
17
16
15
14
13
12
11
10

NC
OCS2_N
PRTPWR2
VDD33CR
VDD18
OCS1_N
PRTPWR1
TEST
VDDA33

Indicates pins on the bottom of the device.

Figure 1.1 USB2512A 36-Pin QFN (Embedded F ootprint)

Revision 1.96 (07-11-08) 6 SMSC USB2512A

DATASHEET

USB 2.0 Hi-Speed 2-Port Hub Controller

Datasheet

Chapter 2 Block Diagram

To Upstream

V

BUS

Bus-Power

Detect/V

BUS

Pulse

Upstream USB

Upstream

PHY

Repeater

Routing & P ort Re-Ordering Logic

Data

24 MH z C rystal

3.3V

1.8V Reg

PLL

SIE

TT

1.8V

To EEPROM or

SM Bus Master

SCKSD

Serial

Inter fa c e

Controller

Port

Controller

PHY#1

USB Data

Downstream

Port #1

OC

Sense

Switch

Driver

LED

Drivers

OC Sense

Switch/LED

Drivers

PHY#2

USB Data

Downstream

Figure 2.1 USB2512A Block Diagram

Port #2

OC

Sense

Switch

Driver

LED

Drivers

OC Sense

Switch/LED

Drivers

SMSC USB2512A 7 Revision 1.96 (07-11-08)

DATASHEET

Chapter 3 Pin Descriptions

3.1 PIN Descriptions

This section provides a detailed description of each signal. The signals are arranged in functional
groups according to their associated interface.

The “N” symbol in the signal name indicates that the active, or asserted, state occurs when the signal
is at a low voltage level. When “N” is not present before the signal name, the signa l is asserted when
at the high voltage level.

The terms assertion and negation are used exclusively. This is done to avoid confusion when worki ng
with a mixture of “active low” and “active high” signals. The term assert, or assertion, indi cates that a
signal is active, independent of whether that level is represented by a high or low voltage. The term
negate, or negation, indicates that a signal is ina ctive.

T able 3.1 USB2512A Pin Descriptions

USB 2.0 Hi-Speed 2-Port Hub Controller

Datasheet

SYMBOL

USBUP_DP

USBUP_DM

VBUS_DET 27

USBDN_DP[2:1]/

&

USBDN_DM[2:1]/

QFN-36

EMB

31
30

4
2

3
1

BUFFER

TYPE DESCRIPTION

UPSTREAM USB INTERFACES

IO-U USB Bus Data

These pins connect to the upstream USB bus data signals such
as the Host port or upstream Hub.

I/O12 Detect Upstream VBUS Power

Detects state of Upstream VBUS power. The SMSC Hub
monitors VBUS_DET to determine when to assert the internal
D+ pull-up resistor which signals 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.

For self-powered applications with a perma nently attached
host, this pin must be connected to 3.3V (typically VDD33).

DOWNSTREAM 2-PORT USB 2.0 INTERFACE

IO-U Hi-Speed USB Data

These pins connect to the downstream USB peripheral devices
attached to the Hub’s port.

PRTPWR[2:1] 16

12

OCS[2:1]_N 17

13

Revision 1.96 (07-11-08) 8 SMSC USB2512A

O12 USB Power Enable

Enables power to USB peripheral devices downstream.
Note: The Hub supports active high power controllers only!

IPU Over-Current Sense

Input from external current monitor indicating an over-cu rrent
condition.

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

DATASHEET

USB 2.0 Hi-Speed 2-Port Hub Controller

Datasheet

Ta b le 3.1 USB2512A Pin Descriptions (continued)

QFN-36

SYMBOL

RBIAS 35 I-R USB Transceiver Bias

SDA/

SMBDATA/

NON_REM1

SCL/

SMBCLK/

EMB

22

24

BUFFER

TYPE DESCRIPTION

A 12.0k
to set the transceiver’s internal bias settings.

SERIAL PORT INTERFACE

I/OSD12 Serial Data / SMB Data & Port Non-removable Strap Option

NON_REM1: Non-removable port strap
option.

If this strap is enabled by package and configuration settings
(see Table 3.2), this pi n will be sampled (in conjunction
with LOCAL_PWR/SUSP_IND/NON_REM0) at RESET_N
negation to determine if ports [2:1] contain permanently
attached (non-removable) devices:

NON_REM[1:0] = ‘00’, All ports are removable.
NON_REM[1:0] = ‘01’, Port 1 is non-removable.
NON_REM[1:0] = ‘10’, Ports 1 & 2 are non-removable.
NON_REM[1:0] = ‘11’, Ports 1 & 2 are non-removable.

I/OSD12 Serial Clock (SCL)

SMBus Clock (SMBCLK)

Ω (+/- 1%) resistor is attached from ground to this pin

CFG_SEL0

HS_IND/

CFG_SEL1

XTAL1/

CLKIN

25

33

Configuration Select_SEL0: The logic state of this multifunction
pin is internally latched on the rising edge of RESET_N
(RESET_N negation), and will determine the Hub configuration
method as described in Table 3.2, "SMBus or EEPROM

Interface Behavior".

I/O12 Hi-Speed Upstream port indicator & Configuration

Programming Select
HS_IND: High Speed Indicator for upstream port connection

speed.
The active state of the LED will be determined as follows:
CFG_SEL1 = ‘0’,

HS_IND is active high,
CFG_SEL1 = ‘1’,

HS_IND is active low,
‘Asserted’ = Hub is connected at HS

‘Negated’ = Hub is connected at FS
CFG_SEL1: The logic state of this pin is internally latched on

the rising edge of RESET_N (RESET_N negation), and will
determine the Hub configuration method as described in

Table 3.2, "SMBus or EEPROM Interface Behavior".

MISC

ICLKx Crystal Input/External Clock Input

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.

SMSC USB2512A 9 Revision 1.96 (07-11-08)

DATASHEET

USB 2.0 Hi-Speed 2-Port Hub Controller

Ta b le 3.1 USB2512A Pin Descriptions (continued)

Datasheet

BUFFER

TYPE DESCRIPTION

SYMBOL

QFN-36

EMB

XTAL2 32 OCLKx Crystal Output

24MHz Crystal
This is the other terminal of the crystal, or a NO CONNECT
when an external clock source is used to drive XTAL1/CLKIN.

Note: This output must not be used to drive any external

RESET_N 26

IS RESET Input

The system can reset the chip by driving this input low. The
minimum active low pulse is 1 us.

When the RESET_N pin is pulled to VDD33, the internal POR
(Power on Reset) is enabled and no external reset circuitry is
required. The internal POR holds the internal logic in reset until
the power supplies are stable.

SUSP_IND/

LOCAL_PWR/

NON_REM0

28

I/O Active/Suspend status LED or Local-Power & Non-removable

Strap Option
Suspend Indicator: Indicates USB state of the hub.

‘negated’ = Unconfigured, or configured and in USB Suspen d
‘asserted’ = Hub is configured, and is active (i.e., not in
suspend)

Local Power: 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.

circuitry other than the crystal circuit.

TEST 1 1

NON_REM0 Strap Option:
If this strap is enabled by package and configuration settings
(see Table 3.2), this pi n will be sampled (in conjunction with
NON_REM1) at RESET_N negation to determine if ports [2:1]
contain permanently attached (non-removable) devices. Also,
the active state of the LED
will be determined as follows:

NON_REM[1:0] = ‘00’, All ports are removable, and the LED is
active high

NON_REM[1:0] = ‘01’, Port 1 is non-removable, and the LED
is active low

NON_REM[1:0] = ‘10’, Ports 1 & 2 are non-removable, and the
LED is active high

NON_REM[1:0] = ‘11’, Ports 1 & 2 are non-removable, and the
LED is active low

IPD TEST pin

XNOR continuity tests all signal pins on the hub. Please contact
your SMSC representative for a detailed description of how this
test mode is enabled and utilized.

Revision 1.96 (07-11-08) 10 SMSC USB2512A

DATASHEET

USB 2.0 Hi-Speed 2-Port Hub Controller

Datasheet

Table 3.2 SMBus or EEPROM Interface Behavior

CFG_SEL1 CFG_SEL0 SMBUS OR EEPROM INTERFACE BEHAVIOR

0 0 Internal Default Configuration

 Strap Options Enabled

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

1 0 Internal Default Configuration

112-Wire I

Table 3.3 USB2512A Power, Ground, and No Connect

PACKAGE SYMBOL 36-QFN EMB

VDD18 14

VDD33PLL 36

descriptors.

 SMBus sla ve address 58 (0101100x)
 Strap Options Disabled
 Al l Settings Controlled by Registers

 Strap Options Enabled
 Bus Power Operation

2

C EEPROMS are supported.

 Strap Options Disabled
 Al l Settings Controlled by Registers

FUNCTION

VDD Core
This pin must have a 1.0μF (or greater) ±20% (ESR <0.1Ω) capacitor to

VSS.
VDD 3.3 PLL Regulator Reference

+3.3V power supply for the PLL. If the internal PLL 1.8V regulator
is enabled, then this pin acts as the regulator input.

VDDPLL18 34

VDD PLL
This pin must have a 1.0μF (or greater) ±20% (ESR <0.1Ω) capacitor to

VSS.

VDDA33 5

10
29

VDD33/VDD33CR 23

15

VDD Analog I/O
+3.3V Filtered analog PHY power, shared between adjacent ports.

VDDIO/VDD 3.3 Core Regulator Reference
+3.3V power supply for the Digital I/O

If the internal core regulator is enabled, then VDD33CR acts as the
regulator input.

NC 6

7
8

No Connect
No trace or signal should be routed or attached to these pins.

9
18
19
20
21

SMSC USB2512A 11 Revision 1.96 (07-11-08)

DATASHEET

3.2 Buffer Type Descriptions

Table 3.4 USB2512A Buffer Type Descriptions

BUFFER DESCRIPTION

I Input.
IPD Input with internal weak pull-down resistor.
IPU Input with internal weak pull-up resistor.

IS Input with Schmitt trigger.

O12 Output 12mA.

OD12 Open drain with 12mA sink.

I/O12 Input/Output buffer with 12mA sink an d 12mA source.

USB 2.0 Hi-Speed 2-Port Hub Controller

Datasheet

I/OSD12

ICLKx XTAL clock input.

OCLKx XTAL clock output.

I-R RBIAS.

I/O-U Analog Input/Output Defined in USB specification.

AIO Analog Input/Output.

Open drain with Schmitt trigger and 12mA sink. Must meet I
Version 2.1 requirements.

2

C-Bus Specification

Revision 1.96 (07-11-08) 12 SMSC USB2512A

DATASHEET

USB 2.0 Hi-Speed 2-Port Hub Controller

Datasheet

Chapter 4 Configuration Options

4.1 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 10 (Hub
Specification) for general details regarding Hub operation and functionality.

The 2-Port Hub provides 1 Transaction Translator (TT) that is shared by both downstream ports
(defined as Single-TT configuration), The TT contains 4 non-periodic b uffers.

4.1.1 Hub Configuration Options

The SMSC Hub supports a large number of features (some are mutually exclusive), 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 (with or without
pin strapping option over-rides). In all cases, the configuration method will be determined by the
CFG_SEL1 and CFG_SEL0 pins immediately after RESET_N negation.

4.1.1.1 Power Switching Polarity

The hub only supports “active high” port power controllers.

4.1.2 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+ resistor if VBUS is not active. If VBUS goes from an active to an inactive state (Not Powered),
the Hub will remove power from the D+ pull-up resistor within 1 0 seconds.

4.2 EEPROM Interface

The SMSC Hub can be configured via a 2-wire (I2C) EEPROM (256x8). (Please see Table 3.1 for
specific details on how to enable configuration via an I

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

Note: The Hub does not have the capacity to write, or “Program,” an external EEPROM. The Hub only
has the capability to read external EEPROMs. The external eeprom will be read (even if it is blank or
non-populated), and the hub will be “configured” with the values tha t are read.

Please see Internal Register Set (Common to EEPROM and SMBus) for a list of data fields available.

4.2.1 Intern al Register Set (Common to EEPROM and SMBus)

2

C EEPROM).

Table 4.1 Internal Default, EEPROM and SMBus Register Memory Map

SMBUS AND

REG

ADDR R/W REGISTER NAME ABBR

00h R /W VID LSB VIDL 24h 0x00
01h R /W VID MSB VIDM 04h 0x00
02h R /W PID LSB PIDL 12h 0x00

SMSC USB2512A 13 Revision 1.96 (07-11-08)

INTERNAL

DEFAULT ROM

EEPROM OR

VALUES

DATASHEET

USB 2.0 Hi-Speed 2-Port Hub Controller

Table 4.1 Internal Default, EEPROM and SMBus Register Memory Map (continued)

SMBUS AND

REG

ADDR R/W REGISTER NAME ABBR

03h R /W PID MSB PIDM 25h 0x00
04h R /W DID LSB DIDL A0h 0x00
05h R /W DID MSB DIDM 0Ah 0x00
06h R/W Config Data Byte 1 CFG1 8Bh 0x00
07h R /W Config Data Byte 2 CFG2 1 0h 0x00
08h R /W Config Data Byte 3 CFG3 0 0h 0x00

09h R/W Non-Removable Devices NRD 00h 0x00
0Ah R/W Port Disa ble (Self) PDS 00h 0x00
0Bh R/W Port Disable (Bus) PDB 00h 0x00
0Ch R/W Max Power (Self) MAXPS 01h 0x00

INTERNAL

DEFAULT ROM

EEPROM OR

VALUES

Datasheet

0Dh R/W Max Power (Bus) MAXPB 32h 0x00
0Eh R/W Hub Controller Max Current

(Self)

0Fh R/W Hub Controller Max Current

(Bus)

10h R/W Power-on Time PWRT 32h 0x00

11 h-F5h R/W Reserved N/A 01h 0x00

F6h R/W Boost_Up BOOSTUP 00h 0x00
F7h R/W Reserved N/A 00h 0x00
F8h R/W Boost_2:0 BOOST20 00h 0x00
F9h R/W Reserved N/A 00h 0x00
FAh R/W Port Swap PRTSP 00h 0x00
FBh R/W Port Remap 12 PRTR12 00h 0x00

FC-FEh R/W Reserved N/A 00h 0x00

FFh R/W Status/Command

Note: SMBus register only

HCMCS 01h 0x00

HCMCB 32h 0x00

STCD 00h 0x00

4.2.1.1 Register 00h: Vendor ID (LSB)

BIT

NUMBER BIT NAME DESCRIPTION

7:0 VID_LSB Least Significant Byte of the Vendor ID. This is a 16-bit value that uniquely

Revision 1.96 (07-11-08) 14 SMSC USB2512A

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.

DATASHEET

USB 2.0 Hi-Speed 2-Port Hub Controller

Datasheet

4.2.1.2 Register 01h: Vendor ID (MSB)

BIT

NUMBER BIT NAME DESCRIPTION

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

4.2.1.3 Register 02h: Product ID (LSB)

BIT

NUMBER BIT NAME DESCRIPTION

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

4.2.1.4 Register 03h: Product ID (MSB)

BIT

NUMBER BIT NAME DESCRIPTION

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

4.2.1.5 Register 04h: Device ID (LSB)

BIT

NUMBER BIT NAME DESCRIPTION

7:0 DID_LSB Least Significant Byte of the Device ID. This is a 16-bit device release

number in BCD format (assigned by OEM). This field is set by th e OEM
using either the SMBus or EEPROM interface options.

4.2.1.6 Register 05h: Device ID (MSB)

BIT

NUMBER BIT NAME DESCRIPTION

7:0 DID_MSB Most Significant By te of the Device ID. This is a 16-bit device release

SMSC USB2512A 15 Revision 1.96 (07-11-08)

number in BCD format (assigned by OEM). This field is set by th e OEM
using either the SMBus or EEPROM interface options.

DATASHEET

USB 2.0 Hi-Speed 2-Port Hub Controller

4.2.1.7 Register 06h: CONFIG_BYTE_1

BIT

NUMBER BIT NAME DESCRIPTION

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

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 the 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 Bus­Powered 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 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.
Please see the description under Dynamic Power for the sel f/bus power
functionality when dynamic power switching is enabled.

Datasheet

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

Note: If Dynamic Power Switching is enabled, this bit is ignored and the
LOCAL_PWR pin is used to determine if the hub is operating from se lf 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 generation of EOF1 when in Full-Speed mode.

2:1 CURRENT_SNS Over Current Sense: Selects current sensing on a port-by-port basis, all

speed device, and forces attachment as Full-speed only (i.e. n o Hi-Speed

support).

0 = High-/Full-Speed

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

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. Note: generation of an EOP at the EOF1

point may prevent a Host controller (operating in FS mode) from placing the

USB bus in suspend.

0 = EOP generation is normal

1 = EOP generation is disabled

ports ganged, or none (only for bus-powered hubs). The ability to support

current sensing on a port or ganged basis is hardware implementation

dependent.

00 = Ganged sensing (all ports together)

01 = Individual port-by-port

1x = Over current sensing not supported (must only be used with Bus-

Powered configurations!)

Revision 1.96 (07-11-08) 16 SMSC USB2512A

DATASHEET

USB 2.0 Hi-Speed 2-Port Hub Controller

Datasheet

BIT

NUMBER BIT NAME DESCRIPTION

0 PORT_PWR Port Power Switching: Enables power switching on all ports simultaneously

(ganged), or port power is individually switch ed on and off on a port- by-port

basis (individual). The ability to support power enabling on a port or ganged

basis is hardware implementation dependent.

0 = Ganged switching (all ports together)

1 = Individual port-by-port switching

4.2.1.8 Register 07h: Configuration Data Byte 2

BIT

NUMBER BIT NAME DESCRIPTION

7 DYNAMIC Dynamic Power Enable: Controls the ability of the Hub to automatically

change from Self-Powered operation to Bus-Powered 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 power

source is available, the Hub will always switch to Self-Powered operation.}

When Dynamic Power switching is enabled, the Hub detects the availability

of a local power source by monitoring the external LOCAL_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 is unavailable) or a Self-

Powered Hub (if local power is available).

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 = 4ms

10 = 8ms

11 = 1 6 m s
3 COMPOUND

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 also be defined as having a "Non-Removable

Device".

Note: When configured via strapping options, declaring a port as

non-removable automatically causes the hub controller to report that

it is part of a compound device.

0 = No

1 = Yes, Hub is part of a compound device

2:0 Reserved Reserved

SMSC USB2512A 17 Revision 1.96 (07-11-08)

DATASHEET

4.2.1.9 Register 08h: Configuration Data Byte 3

BIT

NUMBER BIT NAME DESCRIPTION

7:4 Reserved Reserved

USB 2.0 Hi-Speed 2-Port Hub Controller

Datasheet

3 PRTMAP_EN Port Re-mapping ena ble: Selects the method used by the hub to assign port

2:0 Reserved Reserved

numbers and disable ports.

‘0’ = Standard Mode

‘1’ = Port Re-map mode

4.2.1.10 Register 09h: Non-Removable Device

BIT

NUMBER BIT NAME DESCRIPTION

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

devices. ‘0’ = port is removable, ‘1’ = port i s non-removable.

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.)

When using the internal default option, the NON_REM[1:0] pins will

designate the appropriate ports as being non- removable.

Bit 7= Reserved, always = ‘0’

Bit 6= Reserved, always = ‘0’

Bit 5= Reserved, always = ‘0’

Bit 4= Reserved, always = ‘0’

Bit 3= Reserved, always = ‘1’

Bit 2= 1; Port 2 non-removable

Bit 1= 1; Port 1 non removable

Bit 0= Reserved, always = ‘0’

Revision 1.96 (07-11-08) 18 SMSC USB2512A

DATASHEET

USB 2.0 Hi-Speed 2-Port Hub Controller

Datasheet

4.2.1.11 Register 0Ah: 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.

During Self-Powered operation

(PRTMAP_EN='0'),

disabled, and are not available to be enabled or enumerated by a Host

Controller. The ports can be disabled in any order, the internal logic will

automatically report the correct number of enabled ports to the USB Host,

and will reorder the active ports in order to ensure proper function.

Bit 7= Reserved, always = ‘0’

Bit 6= Reserved, always = ‘0’

Bit 5= Reserved, always = ‘0’

Bit 4= Reserved, always = ‘0’

Bit 3= Reserved, always = ‘1’

Bit 2= 1; Port 2 is disabled

Bit 1= 1; Port 1 is disabled

Bit 0= Reserved, always = ‘0’

this selects the ports which will be permanently

when remapping mode is disabled

4.2.1.12 Register 0Bh: 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.

During Self-Powered operation

(PRTMAP_EN='0'),

disabled, and are not available to be enabled or enumerated by a Host

Controller. The ports can be disabled in any order, the internal logic will

automatically report the correct number of enabled ports to the USB Host,

and will reorder the active ports in order to ensure proper function.

this selects the ports which will be permanently

when remapping mode is disabled

When using the internal default option, the PRT_DIS[1:0] pins will disable the

appropriate ports.

Bit 7= Reserved

Bit 6= Reserved

Bit 5= Reserved

Bit 4= Reserved

Bit 3= Reserved, always = ‘1’

Bit 2= 1; Port 2 is disabled

Bit 1= 1; Port 1 is disabled

Bit 0 is Reserved, always = ‘0’

SMSC USB2512A 19 Revision 1.96 (07-11-08)

DATASHEET

4.2.1.13 Register 0Ch: Max Power For Self Powered Operation

BIT

NUMBER BIT NAME DESCRIPTION

USB 2.0 Hi-Speed 2-Port Hub Controller

Datasheet

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 the hub is
configured as a compound device, and the embedded peripheral reports
0mA in its descriptors.

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

100mA

4.2.1.14 Register 0Dh: 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 the hub is
configured as a compound device, and the embedded peripheral reports
0mA in its descriptors.

4.2.1.15 Register 0Eh: 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 along with the combined
power consumption (from VBUS) of all associated circuitry on the board.
This value does NOT include the power consumption of a permanently
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.

Revision 1.96 (07-11-08) 20 SMSC USB2512A

DATASHEET

USB 2.0 Hi-Speed 2-Port Hub Controller

Datasheet

4.2.1.16 Register 0Fh: 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 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 permanentl y
attached peripheral if the hub is configured as a compound device.

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

4.2.1.17 Register 10h: Power-On Time

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.

4.2.1.18 Register F6h: Boost_Up

BIT

NUMBER BIT NAME DESCRIPTION

7:2 Reserved Reserved
1:0 BOOST_IOUT USB electrical signaling drive strength Boost Bit for the Upstream Port.

‘00’ = Normal electrical drive strength = No boost
‘01’ = Elevated electrical drive strength = Low (approximately 4% b oost)
‘10’ = Elevated electrical drive strength = Medium (approximately 8% boost)
‘11’ = Elevated electrical drive strength = High (a pproximately 12% boost)

Note: “Boost” could result in non-USB Compliant parameters (one

example would be Test J/K levels), the OEM should use a 00 value
unless specific implementation issues require additional signal
boosting to correct for degraded USB signalling levels.

4.2.1.19 Register F8h: Boost_2:0

BIT

NUMBER BIT NAME DESCRIPTION

7:4 Reserved Reserved

SMSC USB2512A 21 Revision 1.96 (07-11-08)

DATASHEET

USB 2.0 Hi-Speed 2-Port Hub Controller

BIT

NUMBER BIT NAME DESCRIPTION

3:2 BOOST_IOUT_2 USB electrical signaling d rive strength Boost Bit for Downstream Port ‘2’.

‘00’ = Normal electrical drive strength = No boost
‘01’ = Elevated electrical drive strength = Low (approximately 4% b oost)
‘10’ = Elevated electrical drive strength = Medium (approximately 8% boost)
‘11’ = Elevated electrical drive strength = High (a pproximately 12% boost)

Note: “Boost” could result in non-USB Compliant parameters (one

example would be Test J/K levels), the OEM should use a 00 value
unless specific implementation issues require additional signal
boosting to correct for degraded USB signalling levels.

1:0 BOOST_IOUT_1 USB electrical signaling d rive strength Boost Bit for Downstream Port ‘1’.

‘00’ = Normal electrical drive strength = No boost
‘01’ = Elevated electrical drive strength = Low (approximately 4% b oost)
‘10’ = Elevated electrical drive strength = Medium (approximately 8% boost)
‘11’ = Elevated electrical drive strength = High (a pproximately 12% boost)

Note: “Boost” could result in non-USB Compliant parameters (one

example would be Test J/K levels), the OEM should use a 00 value
unless specific implementation issues require additional signal
boosting to correct for degraded USB signalling levels.

Datasheet

4.2.1.20 Register FAh: Port Swap

BIT

NUMBER BIT NAME DESCRIPTION

7:0 PRTSP Port Swap: Swaps the Upstream and Downstream USB DP and DM Pins for

ease of board routing to devices and connectors.
‘0’ = USB D+ functionality is associated with the DP pin and D- functionality

is associated with the DM pin.
‘1’ = USB D+ functionality is associated with the DM pin and D- functionality

is associated with the DP pin.
Bit 7= Reserved

Bit 6= Reserved
Bit 5= Reserved
Bit 4= Reserved
Bit 3= Reserved
Bit 2= ‘1’; Port 2 DP/DM is Swapped.
Bit 1= ‘1’: Port 1 DP/DM is Swapped.
Bit 0= ‘1’:Upstream Port DP/DM is Swapped

Revision 1.96 (07-11-08) 22 SMSC USB2512A

DATASHEET

USB 2.0 Hi-Speed 2-Port Hub Controller

Datasheet

4.2.1.21 Register FBh: Port Remap 12

BIT

NUMBER BIT NAME DESCRIPTION

7:0 PRTR12 Port remap register for ports 1 & 2.

When a hub is enumerated by a USB Host Controller, the hub is only
permitted to report how many ports it has; the hub is not permitted to select
a numerical range or assignment. The Host Controller will number the
downstream ports of the hub starting with the number '1', up to the number
of ports that the hub reported having.

The host's port number is referred to as "Logical Port Number" and the
physical port on the hub is the “Physical Port Number". When remappi ng
mode is enabled (see PRTMAP_EN in Register 08h: Configuration Data
Byte 3) the hub's downstream port numbers can be remapped to different
logical port numbers (assigned by the host).

Note: The OEM must ensure that Contiguous Logical Port Numbers are

used, starting from #1 up to the maximum number of enabled ports;
this ensures that the hub's ports are numbered in accordance with
the way a Host will communicate with the ports.

Table 4.2 Port Remap Register for Ports 1 & 2

Bit [7:4] ‘0000’ Physical Port 2 is Disabled

‘0001’ Physical Port 2 is mapped to Logical Port 1
‘0010’ Physical Port 2 is mapped to Logical Port 2
‘0011’

to

‘1111’

Bit [3:0] ‘0000’ Physical Port 1 is Disabled

‘0001’ Physical Port 1 is mapped to Logical Port 1
‘0010’ Physical Port 1 is mapped to Logical Port 2
‘0011’

to

‘1111’

Illegal; Do Not Use

Illegal; Do Not Use

SMSC USB2512A 23 Revision 1.96 (07-11-08)

DATASHEET

4.2.1.22 Register FFh: Status/Command

BIT

NUMBER BIT NAME DESCRIPTION

7:3 Reserved Reserved

2 INTF_PW_DN SMBus Interface Power Down

‘0’ = Interface is active
‘1’ = Interface power down after ACk has completed

USB 2.0 Hi-Speed 2-Port Hub Controller

Datasheet

1 RESET Reset the SMBus Interface and interna l memory back to RESET_N

0 USB_ATTACH USB Attach (and write protect)

assertion default settings.
‘0’ = Normal Run/Idle State

‘1’ = Force a reset of registers to their default state

‘0’ = SMBus slave interface is active
‘1’ = Hub will signal a USB attach event to an upstream device, and the
internal memory (address range 00h-FEh) is “write-protected” to prevent
unintentional data corruption.

4.2.2 I2C EEPROM

The I2C EEPROM interface implements a subset of the I2C Master Specification (Please refer to the
Philips Semiconductor Standard I
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: Extensions to the I
The Hub acts as the master and generates the serial clock SCL, contro ls the bus access (determines

which device acts as the transmitter and which device acts as the receiver), and generates the START
and STOP conditions.

2

C-Bus Specification for details on I2C bus protocols). The Hub’s I2C

2

C Specification are not supported.

4.2.2.1 Implementation Characteristics

The Hub will only access an EEPROM using the Sequential Read Protocol.

4.2.2.2 Pull-Up Resistor

The Circuit board designer is required to place external pull-up resistors (10K Ω 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.

4.2.2.3 I2C EEPROM Slave Address

Slave address is 1010000.
Note: 10-bit addressing is NOT supported.

Revision 1.96 (07-11-08) 24 SMSC USB2512A

DATASHEET

USB 2.0 Hi-Speed 2-Port Hub Controller

Datasheet

4.2.3 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).

4.3 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 connected 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 Block and Read Block protocols are the only valid SMBus protocols for the Hub. The Hub
responds to other protocols as described in Section 4.3.2, "In valid Protocol Response Behavior," on

page 26. Reference the System Management Bus Specification, Rev 1.0.

The SMBus interface is used to read and write the registers in the device. The register set is shown
in Section 4.2.1, "Internal Register Set (Common to EEPROM and SMBus)," on page 13.

4.3.1 Bus Protocols

Typical Write Block and Read Block protocols are shown below. Register accesses are performed
using 7-bit slave addressing, an 8-bit register address field, 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 identifies 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 th e contents of the register that the host
is attempting to read.

Note: Data bytes are transferred MSB first (msb first).

4.3.1.1 Block Read/Write

The Block Write begins with a slave address and a write condition. After the command co de, the host
issues a byte count which describes how many more bytes will follow in the message. If a slave had
20 bytes to send, the first byte would be the number 20 (14h), followed b y the 20 bytes of data. The
byte count may not be 0. A Block Read or Write is allowed to transfer a maximum of 32 data bytes.

Note: For the following SMBus tables:

Denotes Ma ster-to-Slave Denotes Slave-to-Master

SMSC USB2512A 25 Revision 1.96 (07-11-08)

DATASHEET

17118A1

S Slave Address Register AddressWr A

USB 2.0 Hi-Speed 2-Port Hub Controller

Datasheet

...

81 1 188

Byte Count = N

A Data byte 1 A Data byte 2

Block Write

Figure 4.1 Block Write

Block Read
A Block Read differs from a block write in that the repeated start condition exists to satisfy the I2C

specification’s requirement for a change in the transfer direction.

17118

81 1 188

Byte Count = N

Data byte 1 Data b y te 2 Data b y te N

Block Read

Figure 4.2 Block Read

181

A

1

1

SS Slave Address Reg ister AddressWr A

A

A AAA

Data b y te N A P

711

Slave Address Rd A

181

...

P

4.3.2 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 Block and Read Block, which are
described above.

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

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

the Registers Section. See Section 4.3.3 for the response to undefined registers.

4.3.3 General Call Address Resp onse

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

4.3.4 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 exceed s 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 circuit; this simple kind of device typically

resets its communications port after a start or stop condition. The Slave Device Time-Out must
be implemented.

TIMEOUT, MAX

).

TIMEOUT, MIN

). Devices that

Revision 1.96 (07-11-08) 26 SMSC USB2512A

DATASHEET

USB 2.0 Hi-Speed 2-Port Hub Controller

Datasheet

4.3.5 Stretching the SCLK Signal

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

4.3.6 SMBu s Timing

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

4.3.7 Bus Reset Sequence

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

4.3.8 SMBu s Alert Response Address

The SMBALERT# signal is not supported by the Hub.

4.3.8.1 Undefined Registers

The registers shown in Table 4.1 are 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.

4.3.8.2 Reserved Registers

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

4.4 Default Configuration Option:

The SMSC Hub can be configured via its internal default configuration. (please see Section 4.2.1,

"Internal Register Set (Common to EEPROM and SMBus)" for specific details on how to enable default

configuration.)
Please refer to Table 4.1 for the internal defau lt values that are loaded when this option is selected.

4.5 Default Strapping Options:

The USB2512A can be configured via a combination of internal default values and pin strap options.
Please see Table 3.1 and Table 3.2 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 options. The internal d efault
values will be used for the bits & registers that are not controlled by a strapping option pin. Please
refer to Table 4.1 for the internal default values that are loaded when this o ption is selected.

4.6 Reset

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

4.6.1 Intern al POR Hardware Reset

All reset timing parameters are guaranteed by design.

SMSC USB2512A 27 Revision 1.96 (07-11-08)

DATASHEET

4.6.2 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 500μA of current from the upstream USB power source.

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.
The Hub is “operational” 500μs 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).

4.6.2.1 RESET_N for Strapping Option Configuration

USB 2.0 Hi-Speed 2-Port Hub Controller

Datasheet

Hardware

reset

asserted

Read Strap

Options

t1

Drive Strap

Outputs to

inactive

levels

Attach

USB

Upstream

t5 t6

USB Reset

recovery

Idle

t7 t8

Start

completion

request

response

t2

Valid

t3

t4

Don’t Care

Driven by Hub if strap is an output.

RESET_N

VSS

Strap Pins

Don’t Care

VSS

Figure 4.3 Reset_N Timing for Default/Strap Option Mode

Table 4.3 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 1.5 2 μsec
t5 USB Attach (See Note). 100 msec
t6 Host acknowl edges attach and signals USB

100 msec

Reset.

Revision 1.96 (07-11-08) 28 SMSC USB2512A

DATASHEET

USB 2.0 Hi-Speed 2-Port Hub Controller

Datasheet

Table 4.3 Reset_N Timing for Default/Strap Option Mode (continued)

NAME DESCRIPTION MIN TYP MAX UNITS

t7 USB Idle. undefined msec
t8 Completion time for requests (with or without d ata

stage).

Notes:

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

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

 All Power Supplies must have reac hed the operating levels mandated in Chapter 5, DC

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

4.6.2.2 RESET_N for EEPROM Configuration

Hardware

reset

asserted

Read Strap

Options

Read EEPROM

+

Set Options

t4

RESET_N

VSS

t1

t2

t3

Attach

USB

Upstream

USB Reset

recovery

Idle

t5 t6 t7

5 msec

Start

completion

request

response

Figure 4.4 Reset_N Timing for EEPROM Mode

Table 4.4 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 Idle. undefined msec
t7 Completion time for requests (with or without d ata

5 msec

stage).

Notes:

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

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

 All Power Supplies must have reac hed the operating levels mandated in Chapter 5, DC

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

SMSC USB2512A 29 Revision 1.96 (07-11-08)

DATASHEET

4.6.2.3 RESET_N for SMBus Slave Configuration

USB 2.0 Hi-Speed 2-Port Hub Controller

Datasheet

Hardware

RESET_N

VSS

reset

asserted

Reset

Negation

t1

SMBus Code

Load

t2 t4

Hub PHY

Stabilization

t3

Attach

USB

Upstream

USB Reset

recovery

t5

Idle

t6 t7

Start

completion

request

response

Figure 4.5 Reset_N Timing for SMBus Mode

T able 4.5 Reset_N Timing for SMBus Mode

NAME DESCRIPTION MIN TYP MAX UNITS

t1 RESET_N Asserted. 1 μsec
t2 Hub Recovery/Stabilization. 500 μsec
t3 SMBus Code Load (See Note). 250 300 msec
t4 Hub Configuration and USB Attach. 100 msec
t5 Host acknowledges attach and si gnals USB

100 msec

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

5 msec

stage).

Notes:

 For Bus-Powered configurations, the 99.5ms (MAX) i s required, and the Hub and its associated

circuitry must not consume more than 100mA from the upstream USB power source d uring
t2+t3+t4+t5+t6+t7. For Self-Powered configurations, t3 MAX is not applicable and the time to load
the configuration is determined by the external SMBus host.

 All Power Supplies must have reac hed the operating levels mandated in Chapter 5, DC

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

4.6.3 USB Bus Reset

In response to the upstream port signaling a reset to the Hub, the Hub does the following:
Note: The Hub does not propagate the upstream USB reset to downstream devices.

1. Sets default address to 0.

2. Sets configuration to: Unconfigured.

3. Negates PRTPWR[2:1] to all downstream ports.

Revision 1.96 (07-11-08) 30 SMSC USB2512A

DATASHEET

USB 2.0 Hi-Speed 2-Port Hub Controller

Datasheet

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 with the USB
Specification.

SMSC USB2512A 31 Revision 1.96 (07-11-08)

DATASHEET

USB 2.0 Hi-Speed 2-Port Hub Controller

Chapter 5 DC Parameters

5.1 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

T

STOR

-55 150 °C

325 °C Soldering < 10 seconds

V

DDA18PLL,

V

DD18

V

DDA33,

V

DD33PLL,

V

DD33,

V

DD33CR

2.5 V

4.6 V

-0.5 5.5 V

-0.5 4.0 V

-0.5 3.6 V

Note 5.1 Stresses above the specified parameters could cause permanent damage to the device.

This is a stress rating only and functi onal operation of the device at any condition above
those indicated in the operation sections of this specification is not implied .

Note 5.2 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
this possibility exists, it is suggested that a clamp circuit be used.

Voltage

VDD33

VSS

10%

t

10%

t

RT

t

90%

3.3V

90%

Time

100%

Figure 5.1 Supply Rise Time Model

Revision 1.96 (07-11-08) 32 SMSC USB2512A

DATASHEET

USB 2.0 Hi-Speed 2-Port Hub Controller

Datasheet

5.2 Operating Conditions

PARAMETER SYMBOL MIN MAX UNITS COMMENTS

Operating

Temperature

1.8V supply voltage V

3.3V supply voltage V

3.3V supply rise time t

T

A

DDA18PLL

V

DD18

DDA33

V

DDA33PLL

V

DD33

V

DD33CR

RT

0 70 °C Ambient temperature in still air.

1.62 1.98 V

3.0 3.6 V

0400μsSee Figure 5.1

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

DDA33

V

Table 5.1 DC Electrical Characteristics

PARAMETER SYMBOL MIN TYP MAX UNITS COMMENTS

I, IS Type Input Buffer

Low Input Level
High Input Level
Input Leakage
Hysteresis (‘IS’ Only)

V

V

ILI

V

IHI

I

IL

HYSI

2.0

-10

250

0.8

+10
350

V
V

uA

mV

TTL Levels

VIN = 0 to V

DD33

Input Buffer with Pull-Up
(IPU)

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

V
V

I

I

IHI

ILL

IHL

ILI

0.8

2.0

+35

-10

+90
+10

V

V
uA
uA

TTL Levels

VIN = 0
VIN = V

DD33

Input Buffer with Pull­Down (IPD)

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

SMSC USB2512A 33 Revision 1.96 (07-11-08)

V
V

I

I

IHI

ILL

IHL

ILI

0.8

2.0

+10

-35

-10

-90

V

V
uA
uA

TTL Levels

= 0

V

IN

VIN = V

DD33

DATASHEET

USB 2.0 Hi-Speed 2-Port Hub Controller

Table 5.1 DC Electrical Characteristics (con tinued)

PARAMETER SYMBOL MIN TYP MAX UNITS COMMENTS

ICLK Input Buffer

Datasheet

Low Input Level
High Input Level
Input Leakage

O12, I/O12 &I/OSD12
Type Buffer

Low Output Level
High Output Level
Output Leakage
Hysteresis (‘SD’ pad only)

IO-U

(Note 2)

Supply Current
Unconfigured

Hi-Speed Host
Full-Speed Host

Supply Current
Configured

(Hi-Speed Host)

V

ILCK

V

IHCK

I

IL

V

OL

V

OH

I

OL

V

HYSC

I

CCINTHS

I

CCINITFS

1.4

-10

2.4

-10

250

75
65

0.5

+10

0.4

+10
350

85
75

V

V
uA

V

V
uA

mV

mA
mA

VIN = 0 to V

IOL = 12mA @ V
IOH = -12mA @ V
VIN = 0 to V

(Note 1)

DD33

DD33

DD33

DD33

All supplies combined

= 3.3V

= 3.3V

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

Supply Current
Configured

(Full-Speed Host)
1 Port

2 Ports
Supply Current

Suspend
Supply Current

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.

I

HCH1C1

I

HCC2

I

HCH2

I

FCC1

I

FCC2

I

CSBY

I

CRST

115
105
125

130
125
180

mA
mA
mA

All supplies combined

95
95

115
115

mA
mA

300 400 μA All supplies combined

100 180 μA All supplies combined

Revision 1.96 (07-11-08) 34 SMSC USB2512A

DATASHEET

USB 2.0 Hi-Speed 2-Port Hub Controller

Datasheet

CAPACITANCE TA = 25°C; fc = 1MHz; V

DD18

, V

DDPLL

= 1.8V

Table 5.2 Pin Capacitance

LIMITS

PARAMETER SYMBOL MIN TYP MAX UNIT TEST CONDITION

Clock Input

C

Capacitance
Input Capacitance C
Output Capacitance C

XTAL

IN

OUT

2 pF All pins except US B pins (and pins under

test tied to AC ground)
10 pF
20 pF

SMSC USB2512A 35 Revision 1.96 (07-11-08)

DATASHEET

Chapter 6 AC Specifications

6.1 Oscillator/Clock

Crystal: Paralle l Resonant, Fundamental Mode, 24 MHz ±350ppm.
External Clock: 50% Duty cycle ± 10%, 24 MHz ± 350ppm, Jitter < 100ps rms.

C

1

USB 2.0 Hi-Speed 2-Port Hub Controller

Datasheet

XTAL1

(C

S1 =

CB + C

XTAL

)

C

2

Note: C

equals total board/trace capacitance.

B

(C1 + CS1) x (C2 + CS2)

(C

Figure 6.2 Formula to find value of C

6.1.1 SMBu s 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 4.3).

Crystal

Figure 6.1 Typical Crystal Circuit

+ CS1 + C2 + CS2)

1

C

L

1Meg

C

=

and C

1

XTAL2

(C

S2 =

CB + C

L

2

XTAL

)

6.1.2 I2C EEPROM:

Clock frequency is fixed at 60KHz ± 20%.

6.1.3 USB 2.0

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

Revision 1.96 (07-11-08) 36 SMSC USB2512A

DATASHEET

Revision 1.96 (07-11-08) 37 SMSC USB2512A

Chapter 7 Package Outline

DATASHEET

USB 2.0 Hi-Speed 2-Port Hub Controller

Datasheet

Figure 7.1 36-Pin QFN, 6x6mm Body, 0.5mm Pitch