LM3S1918 Luminary Micro, Inc, LM3S1918 Datasheet - Page 63

• Manufacturer Part Number: LM3S1918
• Description: Lm3s1918 Arm Microcontroller
• Manufacturer: Luminary Micro, Inc

Figure 6-3. Main Clock Tree
Note:
6.1.4.2
July 26, 2008
The figure above shows all features available on all Stellaris® Fury-class devices.
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.
MOSCDIS
Main OSC
IOSCDIS
(12 MHz)
(30 kHz)
Internal
Internal
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 76) 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.
OSC
OSC
a
a
(32.768 kHz)
Hibernation
Module
÷ 4
OSCSRC
(400 MHz)
PWRDN
XTAL
PLL
b,d
a
b
Preliminary
BYPASS
÷ 50
÷ 25
b,d
PWMDW
SYSDIV
b,d
a
USEPWMDIV
USESYSDIV
PWRDN
LM3S1918 Microcontroller
a,d
a
PWM Clock
System Clock
ADC Clock
CAN Clock
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