Silabs free Keil PK51 License expires on March,2016. How can it be renewed?
Silicon Labs provides a new license number with new expiration date. Existing licenses will continue to work after 31-Mar-16, but new releases of PK51 published after that date will require re-activation with the new license number.
So, as long as the user doesn't update their installation of Keil, there should be no interruption of service for them.
To update an existing installation to a current license for the PK51 toolchain, please follow these instructions:
1) Go to the following web page: http://pages.silabs.com/lp-keil-pk51.html
2) Fill out the form on the right and click [Submit] to receive a product serial number (PSN). Save this 15 character code for later.
3) If you have already registered your Keil PK51 toolchain using the Simplicity Studio dialog box and registration instructions, please uninstall the PK51 toolchain. To do so in Simplicity Studio, click [Window] > [Preferences] > [Simplicity Studio] > [Toolchains].
4) Click the link that says "Need more toolchains? Customize your installation here..."
5) Scroll down to "Keil 8051 Toolchain (v9.53)" and click Uninstall
6) Restart Simplicity Studio
7) Please reinstall the Keil 8051 toolchain. Repeat Steps 3-6, but this time click [install] next to "Keil 8051 Toolchain (v9.53)"
8) Click [Help] > [Licensing] > [Keil 8051 v9.53]
9) In the dialog box that pops up, click the link ("this form") to go to the Keil Single-User License registration form.
10) Replace the Product Serial # (PSN) in the form with the code you got in step 2 above, and fill out the rest of the form as normal. Submit.
11) Once you receive your email from Keil with the new license ID code (LIC), copy the the LIC into the Simplicity Studio Licensing Helper dialog box from step 9 above and click OK.
12) You should now have a valid license for the PK51 toolchain that does not expire until March 2019.