Ease. Correct me if I am wrong. Qualcomm exclusively uses arm cores . Krait processor 400 m600 800 etc. Snapdragon and the scorpion. armcore a7 cortex a15, a5, a7, arm u7a, arm 11, arm 15.
Texas Instruments omap a9 also licensed for m-3, Cortex mhf, cortex rhf, arm 9 ,arm11
These lists from arm are endless. Arm is the home of the pll. Looking for another core manufacturer that uses a pll besides arm.