Clock System For Xmc7000 Family Mcus; Overview; Clock Resources - Infineon XMC7000 Manual

Clock configuration setup in XMC7000 MCU family

Clock system for XMC7000 family MCUs

2 Clock system for XMC7000 family MCUs
2.1

Overview

The clock system in this series of MCUs is divided into two blocks. One selects the clock resources (such as
external oscillator and internal oscillator) and multiplies the clock (using FLL and PLL). The other distributes
and divides clocks to the CPU cores and other peripheral functions. However, there are some exceptions such
as RTC that can connect directly to a clock resource.
Figure 1 shows the overview of the clock system.
Clock Sources
(External, Internal)
Figure 1 Clock system structure
2.2

Clock resources

The MCU supports two types of resource inputs – internal and external. Each of these internally supports three
types of clocks, respectively.
Internal clock sources (all clocks are enabled by default):
•
Internal main oscillator (IMO): Built-in clock with a frequency of 8 MHz (Typical)
−
Internal low-speed oscillator 0 (ILO0): Built-in clock with a frequency of 32.768 kHz (Typical)
−
Internal low-speed oscillator 1 (ILO1): Has the same function as ILO0, but ILO1 can monitor the clock of
−
ILO0
External clock sources (all clocks are disabled by default):
•
External crystal oscillator (ECO): Uses an external oscillator whose input frequency range is between 8
−
and 33.34 MHz
Watch crystal oscillator (WCO): Uses an external oscillator whose frequency is stable 32.768 kHz, mainly
−
used by the RTC module
External clock (EXT_CLK): The EXT_CLK is a 0.25 MHz to 80 MHz range clock that can be sourced from a
−
signal on a designed I/O pin. This clock can be used as the source clock for either PLL or FLL or can be
used directly by the high-frequency clocks.
For more details on functions such as IMO, PLL, and so on, and numerical values such as frequency, see the
XMC7000 MCU family architecture reference manual
Application note
Clock System
Clock Selection
and Multiplier
Clock Distribution/
Division
and the datasheet.
5
Internal Circuit
(CPU Core, Peripheral Functions,
and so on)
002-34253 Rev. *C
2023-11-08