LM3S2276 Datasheet, PDF (194/785 Pages) Texas Instruments – Stellaris® LM3S2276 Microcontroller

System Control
Bit/Field
10:6
5:4
Name
XTAL
OSCSRC
Type
R/W
R/W
Reset
0xB
Description
Crystal Value
This field specifies the crystal value attached to the main oscillator. The
encoding for this field is provided below. Depending on the crystal used,
the PLL frequency may not be exactly 400 MHz (see Table
21-9 on page 724 for more information).
Value Crystal Frequency (MHz) Not Crystal Frequency (MHz) Using
Using the PLL
the PLL
0x00
1.000
reserved
0x01
1.8432
reserved
0x02
2.000
reserved
0x03
2.4576
reserved
0x04
3.579545 MHz
0x05
3.6864 MHz
0x06
4 MHz
0x07
4.096 MHz
0x08
4.9152 MHz
0x09
5 MHz
0x0A
5.12 MHz
0x0B
6 MHz (reset value)
0x0C
6.144 MHz
0x0D
7.3728 MHz
0x0E
8 MHz
0x0F
8.192 MHz
0x10
10.0 MHz
0x11
12.0 MHz
0x12
12.288 MHz
0x13
13.56 MHz
0x14
14.31818 MHz
0x15
16.0 MHz
0x16
16.384 MHz
0x1
Oscillator Source
Selects the input source for the OSC. The values are:
Value Input Source
0x0 MOSC
Main oscillator
0x1 IOSC
Internal oscillator (default)
0x2 IOSC/4
Internal oscillator / 4
0x3 30 kHz
30-KHz internal oscillator
For additional oscillator sources, see the RCC2 register.
194
November 17, 2011
Texas Instruments-Production Data