Hi JDL45, glad to help you with your question! I briefly covered it in a previous post which you can find HERE. On that question we were talking about the PAC52xx family of devices but I do mention that the PAC55xx family of devices, revolving around our ARM Cortex M4F 150 MHz CPU can execute code at 150 MHz when the code resides in RAM. The PLL can operate to as high as 300 MHz, so the TIMERs can be clocked as fast as 300 MHz as well. Hope the info helps!