Filter
Top Products
High Speed Inter-Chip USB 2.0 Hub and Flash Media Controller
Datasheet
Revision 1.0 (06-01-09) 28 SMSC USB4640/USB4640i
DATASHEET
Chapter 8 Configuration Options
8.1 Hub
SMSC’s USB 2.0 hub is fully compliant to the Universal Serial Bus Specification available from the
USB Implementer’s Forum found at http://www.usb.org (Revision 2.0 April 27, 2000 and the 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 hub provides 1 transaction translator (TT) that is shared by both
downstream ports defined as a single-TT configuration. The TT contains 4 non-periodic buffers.
8.1.1 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 two principal
ways to configure the hub:
via the internal default settings or
by settings stored in an external EEPROM or SPI Flash device.
8.1.1.1 Power Switching Polarity
The hub will only support active high power controllers.
8.2 Card Reader
The SMSC USB4640/USB4640i is fully compliant with the following flash media card reader
specifications:
Secure Digital 2.0 / MultiMediaCard 4.2
-SD 2.0, HS-SD, HC-SD
-TransFlash™ and reduced form factor media
-1/4/8 bit MMC 4.2
Memory Stick 1.43
Memory Stick Pro Format 1.02
Memory Stick Pro-HG Duo Format 1.01
-Memory Stick, MS Duo, HS-MS, MS Pro-HG, MS Pro
Memory Stick Duo 1.10
xD-Picture Card 1.2
8.3 System Configurations
8.3.1 EEPROM/SPI Interface
The USB4640/USB4640i can be configured via a 2-wire (I
2
C) EEPROM (512x8) or an external SPI
flash device containing the firmware for the USB4640/USB4640i. If an external configuration device
does not exist the internal default values will be used. If one of the external devices is used for
configuration, the OEM can update the values through the USB interface. The hub will then “attach”
to the upstream USB host.