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1. Download and install your IAR copy following the standard installation procedure.
2. Create the IAR_ARM_BASE environment variable (see "Creating Environment Variables" below Setting up the IAR_ARM_BASE Environment Variable) and set it to contain base address of your installation, e.g. IAR_ARM_BASE=C:\Program Files (x86)\IAR Systems\Embedded Workbench 6.4 
3. For IAR versions prior to 7.4 (for IAR versions >= 7.4, these directories already exist):
   1. Create the IAR_ARM_BASE\arm\config\flashloader\Linear\DustNetworks\ directory
   2. Create the IAR_ARM_BASE\arm\config\linker\Linear\DustNetworks\ directory
4. For IAR versions prior to 7.4, copy the files below from your 

   Include Page
   _def_ocsdk _def_ocsdk

    installation directory (for IAR >= 7.4, these files are already present and this step is not needed):
   1. Copy the files in \tools\flash_loader\ -->  to IAR_ARM_BASE\arm\config\flashloader\Linear\DustNetworks\
   2. Copy \linker_configuration\Eterna.icf  -->  to IAR_ARM_BASE\arm\config\linker\Linear\DustNetworks\

Creating Environment Variables

In Windows 7 (other versions should be a similar procedure):

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Under either User or System variables, select the New... button

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Next Step: Download the SDK