Industrial Temperature Rated USB 2.0 High-Speed 3-Port Hub Controller
Datasheet
Revision 1.98 (11-19-07)
18
SMSC USB2513i
DATASHEET
Chapter 4 Configuration Options
4.1
3-Port Hub
SMSC’s USB 2.0 3-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.
For performance reasons, the 3-Port Hub provides 1 Transaction Translator (TT) per port (defined as
Multi-TT configuration), divided into 4 non-periodic buffers per TT.
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_SEL2, CFG_SEL1 and CFG_SEL0 pins immediately after RESET_N negation.
4.1.1.1
Power Switching Polarity
The selection of active state “polarity” for the PRTPWR pins is made by a strapping option only (the
PRTPWR_POL pin).
Note:
If PRTPWR_POL is not an available pin on the package, the hub will support active high power
controllers only!
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),
Hub will remove power from the D+ pull-up resistor within 10 seconds.
4.2
36 QFN and 48 QFN Feature Differences
Table 4.1 36 QFN and 48 QFN Feature Differences
36 QFN
48 QFN
FEATURE
N/A
Available
48MHz clock input mode
N/A
Available
External 1.8V regulators
N/A
Available
Port LED Indicators
N/A
Available
Port Swap Strapping Options
Available
N/A
Only Active High Port Power Control is supported in 36 QFN package
Available
N/A
Boost Default Level is used; see
