https://devzone.nordicsemi.com/f/nordic-q-a/3029/keil-v5-cmsis-v4-1Hello, I&#39;m new to the nRF51 modules and I just started with nRF51422 module. I have Keil uVision v5.11.1.0 with MDK Pro v5.11.0. I have installed nRF SDK - nrf51_sdk_v5_2_0_39364.msi and I had to modify PDSC file according to this issue. Everythingen-USTelligent Community 13Fri, 31 Oct 2014 16:36:59 GMThttps://devzone.nordicsemi.com/thread/11380?ContentTypeID=1Fri, 31 Oct 2014 16:36:59 GMT137ad170-7792-4731-bb38-c0d22fbe4515:26eda534-8953-466c-8c75-f586c0a79ef1Ron Wedge<p>Looking at Keil&#39;s AN266, this App note was written specifically for STmicroelectronic parts in mind, not Nordic ones.</p><div style="clear:both;"></div>