The Definitive Guide to the ARM Cortex-M3

CHAPTER 14 Other Cortex-M3 Features

In This Chapter:

• The SYSTICK Timer

• Power Management

• Multiprocessor Communication

• Self-Reset Control

The SYSTICK Timer

The SYSTICK register in the NVIC was covered briefly in Chapter 8. As we saw, the SYSTICK timer is a 24-bit down counter. Once it reaches zero, the counter loads the reload value from the RELOAD register. It does not stop until the enable bit in the SYSTICK Control and Status register is cleared.

Figure 14.1 SYSTICK Registers in the NVIC

The Cortex-M3 processor allows two different clock sources for the SYSTICK counter. The first one is the core free-running clock (not from the ...