Ultra Fast USB 2.0 Multi-Format Flash Media Controller/USB Hub Combo

Chapter 7 Configuration Options

7.1Hub

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.

The hub provides 1 transaction translator (TT) that is shared by both downstream ports (defined as single-TT configuration). The TT contains 4 non-periodic buffers.

7.1.1Hub 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; The internal default settings or by settings stored in an external EEPROM or SPI Flash device.

7.1.1.1Power Switching Polarity

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

7.1.2VBus 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 10 seconds.

7.2Card Reader

The SMSC USB2640/USB2641 is fully compliant with the following flash media card reader specifications:

„Memory Stick Specification 1.43

„Memory Stick Pro Format Specification 1.02

„Memory Stick Pro-HG Duo Format Specification 1.01 -Memory Stick, MS Duo, HS-MS, MS Pro-HG, MS Pro

„xD-Picture Card 1.2 compliant

„Secure Digital 2.0 / MultiMediaCard Specification 4.3 -SD 2.0, HS-SD, HC-SD

-TransFlash™ and reduced form factor media -1/4/8 bit MMC 4.2

7.3System Configurations

7.3.1EEPROM/SPI Interface

The USB2640/USB2641 can be configured via a 2-wire (I2C) EEPROM (256x8) or an external SPI flash device containing the firmware for the USB2640/USB2641. If an external configuration device does not exist the internal default values will be used. If one of the external devices is used for

SMSC USB2640/USB2641

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Revision 2.0 (10-03-08)

 

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