Simplicity Studio currently does not support IAR ARM toolchains above version 7.80.x, so if the desire is to use the IAR ARM toolchain with Simplicity Studio, then IAR ARM version 7.80 will need to be installed. It can be installed parallel to a version 8.x installation, so that version 8.x can be used for non-Simplicity Studio work. It can be hard to find the older installer on the IAR website, so this is a direct link to the version 7.80.2 installer:
NOTE: A license for the IAR ARM toolchain must be purchased separately from IAR.
After installing the IAR ARM toolchain, if 32-bit product support (MCU or Wireless) has been installed, the toolchain should be automatically detected the next time Simplicity Studio is started. If it isn't detected then it can be added manually by clicking the [Settings] icon from the Launcher perspective and then selecting [Simplicity Studio] > [Toolchains] and clicking the [Add...] button and browsing to the root IAR Embedded Workbench folder (default for Windows: "C:\Program Files (x86)\IAR Systems\Embedded Workbench 7.5\").
Silicon Labs is planning to add support for IAR versions 8.x to Simplicity Studio and the 32-bit SDKs later this year (2018).
Please note that when first installing Simplicity Studio on a 4K monitor, the entire installation option dialog box may not appear correctly. During a first time installation, after the Log In dialog box, a dialog box with two options ("Install by Device" or "Install by Product Group") will be displayed:
But on 4K monitors the second box for "Install by Product Group" might be clipped like this:
Clicking on the small visible portion of the "Install by Product Group" box will still allow the installation to be completed using that installation method.
Install by Device - This option is best when wanting to only install the minimum number of files for a small group of products is desired and the exact products are known in advance.
Install by Product Group - This is the recommended installation option, it will install broad product support for the entire product group from this selection of products:
Note after the first time installation, when choosing the Update Software icon, a third installation category "Package Manager" will be displayed:
As the text under Package Manager says, the Package Manager allow Product Updates to be installed as well as new SDKs or Tools to be installed or uninstalled.
Silicon Labs hopes this information will help in deciding which installation method to use and in cases were the clipped installation option box is seen.