LM3S3768 Luminary Micro, Inc, LM3S3768 Datasheet - Page 88

• Manufacturer Part Number: LM3S3768
• Description: Lm3s3768 Arm Microcontroller
• Manufacturer: Luminary Micro, Inc

System Control
88
Bit/Field
10:6
5:4
3:2
OSCSRC
reserved
Name
XTAL
Type
R/W
R/W
RO
Reset
0xB
0x1
0x0
Preliminary
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.
Oscillator Source
Picks among the four input sources for the OSC. The values are:
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.
Value
Value
0x0
0x1
0x2
0x3
0x0A
0x0B
0x0C
0x0D
0x0E
0x00
0x01
0x02
0x03
0x04
0x05
0x06
0x07
0x08
0x09
0x0F
0x10
0x11
0x12
0x13
0x14
0x15
0x16
Input Source
Main oscillator
Internal oscillator (default)
Internal oscillator / 4 (this is necessary if used as input to PLL)
30 KHz internal oscillator
Crystal Frequency (MHz)
Not Using the PLL
1.8432
2.4576
1.000
2.000
6 MHz (reset value)(USB)
10.0 MHz (USB)
12.0 MHz (USB)
16.0 MHz (USB)
3.579545 MHz
14.31818 MHz
4 MHz (USB)
5 MHz (USB)
8 MHz (USB)
3.6864 MHz
4.9152 MHz
7.3728 MHz
12.288 MHz
16.384 MHz
4.096 MHz
6.144 MHz
8.192 MHz
13.56 MHz
5.12 MHz
Crystal Frequency (MHz)
Using the PLL
reserved
reserved
reserved
reserved
June 02, 2008