IAR Embedded Workbench for MSP430 4.21 FET driver downgrade

Technical Note 52827






11/6/2015 10:45 AM


In IAR Embedded Workbench for MSP430 version 5.10 and newer, the "Windows driver package" (umpusbvista) for the FET-USB is used. 


That USB driver is incompatible with IAR Embedded Workbench for MSP430 version 4.21 and older.


The USB driver installed by IAR Embedded Workbench for MSP430 version 5.xx can be uninstalled and replaced by the USB driver from 4.xx.

Solution CAN NOT be used for...

...Windows systems that are 64-bit. All 64-bit systems must use the "Windows driver package" (umpusbvista) USB driver. (That is, the driver installed by IAR Embedded Workbench for MSP430 5.xx).

The solution, step-by-step

  • Start Windows Add/Remove Programs and uninstall the "Windows driver package" (umpusbvista). 
  • Connect the USB-FET emulator to the computer. After a while, the Windows Found New Hardware Wizard will start. 
  • In the Wizard, select the option that says "I will point out which driver to use". (In Windows XP that corresponds to the radio-button "No not this time". (See again the picture above.)
  • In a later Wizard-step, browse to the old (IAR Embedded Workbench for MSP430 version 4.21 or older) USB driver. That driver is found in the \430\drivers\TIUSBFET\WinXP\ directory.
  • There will be a Windows warning for "Compatibility with XP". Push the "Continue Anyway" button. 
  • The USB driver is now installed. Windows Device Manager will look as in the picture below.
  • Now, IAR Embedded Workbench for MSP430 version 4.21 will be able to use the USB-FET emulator.


Will this old USB driver work with IAR Embedded Workbench for MSP430 version 5.xx?

Yes. On a 32-bit Windows system, the old USB driver will work with the newer IAR Embedded Workbench for MSP430 version 5.xx.

I get Firmware Update messages each time I change from 4.xx to 5.xx! Is that correct?

Yes, this is the correct behavior. The FET DLL file(s) for 4.xx and 5.xx are different, and thus the firmware must be updated for each change between 4.xx and 5.xx.

After following this Technical Note, is there a risk that the old USB driver is removed?

Yes and no.

No, the driver will not be removed as long the computer is not changed.

Yes, the driver will be removed if IAR Embedded Workbench for MSP430 5.xx or a newer version is (re-)installed. (It is part of the installation to replace the USB-driver with the more modern "umpusbvista" driver. If the driver was updated, perform the steps in this Technical Note once again.


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