https://devzone.nordicsemi.com/f/nordic-q-a/16770/which-rtxos-lib-file-choosed-to-implement-in-nrf52832-applicationhi, i want to implement rtxos in my nrf52832 application. one of the nrf52832&#39;s feature is ARM Cortex -M4 32-bit processor with FPU, 64 MHz. my question is, why the nrf52832 rtx demo offered by nordic choosed RTX_CM3.lib instead of RTX_CM4.lib?en-USTelligent Community 13Fri, 30 Sep 2016 09:04:05 GMThttps://devzone.nordicsemi.com/thread/64148?ContentTypeID=1Fri, 30 Sep 2016 09:04:05 GMT137ad170-7792-4731-bb38-c0d22fbe4515:6eaff352-8d28-4c9d-9624-472840d47643J&#248;rgen Holmefjord<p>Hi,</p> <p>The difference between the lib-files is described on <a href="http://www.keil.com/support/man/docs/rlarm/rlarm_ar_libfiles.htm">ARM Library Documentation</a>. As you can see, the RTX_CM3.lib file supports <em>&quot;microcontrollers based on Cortex<span class="emoticon" data-url="https://devzone.nordicsemi.com/cfs-file/__key/system/emoji/2122.svg" title="Tm">&#x2122;</span>-M3 and Cortex<span class="emoticon" data-url="https://devzone.nordicsemi.com/cfs-file/__key/system/emoji/2122.svg" title="Tm">&#x2122;</span>-M4 without FP extension - Little Endian&quot;</em>.</p> <p>I am not exactly sure why the blinky_rtx example does not work with RTX_CM4.lib that is provided with SDK12, but it might originate from <a href="https://devzone.nordicsemi.com/question/45354/error-in-svc-handler-in-nrf52-sdk-091-with-s132/">this problem</a>. If you want, you can try the solution suggested by my collegue in <a href="https://devzone.nordicsemi.com/question/44798/rtx-support-in-the-nrf52-sdk/?answer=45698#post-id-45698">this answer</a>. It did compile for me, but the blinking of the LEDs were a bit slow compared to the RTX_CM3 version.</p> <p>Are you planning to use any of the FP extensions? I would recommend that you start with the example application provided in the SDK and build/integrate your application in this.</p> <p>Best regards,</p> <p>Jørgen</p><div style="clear:both;"></div>