Fan Speed Control with the EMC2102 Device

Notes:

1.The EVB-EMC2102 needs to be configured using the USB SMBus Bridge to work properly. If in the device selection window the Master Controller type is set to I/O Controller Hub then the "Supported company ID on device not found" message will pop-up again.

2.Disconnecting the USB cable and reconnecting it without restarting the ChipMan may cause register reading errors (all zeros). This problem can be cleared by re-selecting the EMC2102 device through the device selection window (Options -> Select Device).

3.The SMBus Slave Address could vary depending on the device. If a correct XML file is installed, the ChipMan should be able to select the correct slave address automatically. Refer to the device datasheet for more details about the SMBus protocol and its configurations.

4.The SMSC ChipMan application allows viewing and changing register values for a variety of devices. The ChipMan software only needs to be installed once to support all of these devices. The list of supported devices may be found in the pulldown menu under Options -> Select Device.

The next step will be to load the CMF file. Simply select File at the top of the window, and "Import" from the pull-down menu. A pop-up window will let the user to locate the right CMF.

Select the appropriate file and click "open". The CMF file will then load up the values into the EMC2102 device.

SMSC provides all CMF files for the operation experiments introduced in this user manual to help customers to evaluate the EMC2102 device. Customers can also export their own configurations to CMF files through the pull-down menu File -> Export/Export As.

The CMF file used for the Experiment 1 is EMC2102_manual.cmf.

To ensure the ChipMan application and the EMC2102 are communicating, select File -> Import and then select the file emc2102_manual.cmf. This will import a configuration file to disable EMC2102’s RPM control function and then set a valid fan control output value. The on-board DC fan’s speed will be reduced to about 5000 rpm at this time.

Select "3: Fan Settings" in the ChipMan window by double-clicking. The window as shown in Figure 5.5, "Changing Fan Speed" will open. Double-click the "last value" of Fan Driver Setting register (51h) and enter a new drive value (should be greater than 9Ah for the on-board DC fan). The fan should respond, and the TACH Reading register (58h) should indicate an RPM reading.

It is recommended to set Autorefresh Registers option in ChipMan for all experiments in this user manual. Select Options -> Autorefresh registers.

SMSC EMC2102

USER MANUAL

Revision 0.2 (09-17-07)

11