Hands-On RTOS with Microcontrollers

The CPU clock rate

Since we're limiting our discussion to MCUs with the same underlying architecture, an MCU with a faster core clock rate will execute the same set of pure software functions faster than one with a slower clock rate. Notice the keyword pure in the previous statement—sometimes, there are on-board hardware peripherals that can make a huge difference to execution speed that have nothing to do with the CPU clock rate (such as the hardware floating point and DSP functionality available on the Cortex-M4 core). 

Another thing to be mindful of is the absolute maximum clock rate of the device versus the practical clock rate for an application. For example, some MCUs' maximum clock frequency is incompatible with generating an internal ...