Question:

Is there a way that I can obtain older 32-bit MCU SDK versions in Simplicity Studio?

Answer:

It should be possible to download and use an older SDK version in Simplicity Studio when developing code for 32-bit EFM32 devices in Simplicity Studio.  The following steps should allow a user to obtain older SDK versions:

1) In the Simplicity Studio [Launcher] perspective, click the [Software Update] button:

2) If necessary, click on [Package Manager]:

3) In the [Package Manager] window, select “32 bit MCU” from the [Categories] dropdown menu and select “All” from the [Version] dropdown menu:

4) Select the desired SDK version and click [Install].  Once installation is complete, that SDK should be available for use in example projects as well as empty C8051/EFM8 projects. 

As of this writing, it appears that 32 bit MCU SDK versions as far back as 32 bit MCU SDK – 4.4.0 and Gecko SDK v4.4.0 – 4.4.0 are available using this method.