AN663 Overview
Key Features
- a highly configurable clock structure
- The advanced highperformance bus (AHB) and advanced peripheral bus (APB) have many options available for clocking
- In addition, firmware can disable most peripheral clocks to save power
- The clock to the module must be enabled before firmware can modify the registers
- The first initialization step in all peripheral initialization routines should enable the clock to the module
- Clock Sources The AHB drives the core and memory on ARM® Cortex™-M3 devices
- The APB drives the peripherals and peripheral registers
- The APB clock is either equal to AHB or a divide by 2 version of it, so it is always synchronized with the AHB clock
- Table 1 describes the oscillators that can serve as clock sources for the AHB bus
