Latest revision as of 06:57, 26 January 2012

RCC - reset and clock control

Clock Tree (Click to enlarge)

STM32F107VC is a Connectivity Line Device and this register refers to Chapter 8 in The Reference manual.

Reset

There are three types of reset

1. System Reset
2. Power Reset
3. Backup Domain Reset

Se section 8.1 of the The Reference manual for further information.

Clocks

Three different clock sources can be used to drive the system clock (SYSCLK):

• HSI oscillator clock
• HSE oscillator clock
• PLL clock

Clock Modes

• The SYSCLK and Cortex M3 Clock can be configured in five different paths. See Clock Paths
• Clock Modes example

HSI - High Speed Internal Clock

The HSI clock signal is generated from an internal 8 MHz RC Oscillator and can be used directly as a system clock or divided by 2 to be used as PLL input.

HSE - High Speed External clock

The high speed external clock signal (HSE) can be generated from two possible clock sources:

• HSE external crystal/ceramic resonator
• HSE user external clock

The MCBSTM32C evaluation board has a 25Mhz on board crystal for HSE Clock.

PLL - Phase Locked Loops

The main PLL provides a frequency multiplier starting from one of the following clock sources:

• HSI clock divided by 2
• HSE or PLL2 clock through a configurable divider

Example

• Clock mode 1 and clock mode 5 example