LM3S3748 Datasheet, PDF (88/753 Pages) List of Unclassifed Manufacturers – Microcontroller

System Control
Bit/Field
10:6
5:4
3:2
Name
XTAL
OSCSRC
reserved
Type
R/W
R/W
RO
Reset
0xB
Description
Crystal Value
This field specifies the crystal value attached to the main oscillator. The
encoding for this field is provided below.
Frequencies that may be used with the USB interface are indicated in
the table. To function within the clocking requirements of the USB
specification, a crystal of 4, 5, 6, 8, 10, 12, or 16 MHz must be used.
Value
0x00
0x01
0x02
0x03
0x04
0x05
0x06
0x07
0x08
0x09
0x0A
0x0B
0x0C
0x0D
0x0E
0x0F
0x10
0x11
0x12
0x13
0x14
0x15
0x16
Crystal Frequency (MHz) Crystal Frequency (MHz)
Not Using the PLL
Using the PLL
1.000
reserved
1.8432
reserved
2.000
reserved
2.4576
reserved
3.579545 MHz
3.6864 MHz
4 MHz (USB)
4.096 MHz
4.9152 MHz
5 MHz (USB)
5.12 MHz
6 MHz (reset value)(USB)
6.144 MHz
7.3728 MHz
8 MHz (USB)
8.192 MHz
10.0 MHz (USB)
12.0 MHz (USB)
12.288 MHz
13.56 MHz
14.31818 MHz
16.0 MHz (USB)
16.384 MHz
0x1
Oscillator Source
Picks among the four input sources for the OSC. The values are:
Value Input Source
0x0 Main oscillator
0x1 Internal oscillator (default)
0x2 Internal oscillator / 4 (this is necessary if used as input to PLL)
0x3 30 KHz internal oscillator
0x0
Software should not rely on the value of a reserved bit. To provide
compatibility with future products, the value of a reserved bit should be
preserved across a read-modify-write operation.
88
April 08, 2008
Preliminary