LM3S6952 Datasheet, PDF (75/626 Pages) Texas Instruments – Stellaris LM3S6952 Microcontroller

Stellaris® LM3S6952 Microcontroller
Figure 6-5. Main Clock Tree
USEPWMDIV ^a
PWMDW ^a
MOSCDIS ^a
Main OSC
IOSCDIS^a
Internal
OSC
(12 MHz)
Internal
OSC
(30 kHz)
Hibernation
Module
(32.768 kHz)
XTAL^a
PWRDN ^b
PLL
(400 MHz)
÷4
OSCSRC^b,d
÷2
BYPASS ^b,d
÷ 25
USESYSDIV ^a,d
SYSDIV ^b,d
PWRDN
÷ 50
PWM Clock
System Clock
ADC Clock
CAN Clock
a. Control provided by RCC register bit/field.
b. Control provided by RCC register bit/field or RCC2 register bit/field, if overridden with RCC2 register bit USERCC2.
c. Control provided by RCC2 register bit/field.
d. Also may be controlled by DSLPCLKCFG when in deep sleep mode.
Note: The figure above shows all features available on all Stellaris® Fury-class devices.
6.1.4.2
Crystal Configuration for the Main Oscillator (MOSC)
The main oscillator supports the use of a select number of crystals. If the main oscillator is used by
the PLL as a reference clock, the supported range of crystals is 3.579545 to 8.192 MHz, otherwise,
the range of supported crystals is 1 to 8.192 MHz.
The XTAL bit in the RCC register (see page 88) describes the available crystal choices and default
programming values.
Software configures the RCC register XTAL field with the crystal number. If the PLL is used in the
design, the XTAL field value is internally translated to the PLL settings.
April 05, 2010
75
Texas Instruments-Production Data