LM3S3739 Luminary Micro, Inc, LM3S3739 Datasheet - Page 83

• Manufacturer Part Number: LM3S3739
• Description: Lm3s3739 Arm Microcontroller
• Manufacturer: Luminary Micro, Inc

June 02, 2008
Bit/Field
10:6
11
BYPASS
Name
XTAL
Type
R/W
R/W
Reset
0xB
1
Preliminary
Description
PLL Bypass
Chooses whether the system clock is derived from the PLL output or
the OSC source. If set, the clock that drives the system is the OSC
source. Otherwise, the clock that drives the system is the PLL output
clock divided by the system divider.
Note:
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
0x0A
0x0B
0x0C
0x0D
0x0E
0x00
0x01
0x02
0x03
0x04
0x05
0x06
0x07
0x08
0x09
0x0F
0x10
0x11
0x12
0x13
0x14
0x15
0x16
The ADC must be clocked from the PLL or directly from a
14-MHz to 18-MHz clock source to operate properly. While
the ADC works in a 14-18 MHz range, to maintain a 1 M
sample/second rate, the ADC must be provided a 16-MHz
clock source.
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
LM3S3739 Microcontroller
Crystal Frequency (MHz)
Using the PLL
reserved
reserved
reserved
reserved
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