EVB-USB2240-IND Evaluation Board Revision A
2 Getting Started
The EVB-USB2240-IND is configured by internal default registers. In this configuration it operates as a generic self or bus-powered USB 2.0 Media Controller with SMSC standard VID/PID/DID settings.
2.1Configuration
The SMSC EVB-USB2240-IND is designed for flexible configuration solutions. It demonstrates functionality with default internal register settings, configurable external EEPROM, and EEPROM configuration update via the USB host. When an EEPROM is attached, the USB2240 will auto detect the interface and configure itself with the EEPROM contents. The EVB-USB2240-IND demonstrates how the EEPROM configuration settings can be changed without physical EEPROM removal.
2.1.1Configuration Source - Internal Default
When the device does not see an EEPROM upon power-up, the EVB-USB2240-IND uses internal default register settings; it sets the Vendor ID, Product ID, Language ID, and Device ID, and a few other choices. An improved feature with the USB2240 is that external passive components are not needed to set the IC configuration mode.
2.1.2Configuration Source - External EEPROM
Upon power-up the USB2240 looks for an attached EEPROM on its I2C interface. The EVB-USB2240- IND provides an 8-pin DIP socket IC U2 for an external EEPROM of type 24C02 to customize the Media Controller’s settings. The EEPROM contains 256 bytes of user customizable settings. Among the settings are Vendor ID, Product ID, and Device ID numbers. For details on the fields please see the USB2240 Software Release notes.
2.1.3Power Source - Self/Bus Powered
The EVB-USB2240-IND supports both self and bus powered operation. By default the EVB-USB2240- IND is populated for bus powered operation. Refer to Table 2.1 for resistor population options to change the power source.
Table 2.1 Population Options for Self or Bus Powered Operation
POWER SOURCE | R14 | R16 |
| | |
Bus Powered (Default) | Populate | Do not Populate |
| | |
Self Powered | Do not Populate | Populate |
| | |
2.1.4Clock Source - Crystal or Resonator
The EVB-USB2240-IND is designed to support either a crystal or a resonator. Because crystals offer more accurate center frequency, the evaluation board is populated with a crystal and its supporting decoupling capacitors. Some customers prefer lower cost resonators, which eliminates the need for external decoupling, lowering bill of material expense.
Revision 0.2 (06-03-08) | 4 | SMSC EVB-USB2240-IND |
| USER MANUAL | |