LM3S815_06 Datasheet, PDF (84/412 Pages) List of Unclassifed Manufacturers – Microcontroller

System Control
Bit/Field
9:6
Name
XTAL
Type
R/W
5:4
OSCSRC
R/W
Reset Description
0xB
This field specifies the crystal value attached to the main
oscillator. The encoding for this field is provided in Table 6-4
on page 84.
Oscillator-Related Bits
0x0
Picks among the four input sources for the OSC. The
values are:
Value
00
01
Input Source
Main oscillator (default)
Internal oscillator
10
Internal oscillator / 4 (this is necessary if used
as input to PLL)
11
reserved
3
IOSCVER
R/W
2
MOSCVER
R/W
1
IOSCDIS
R/W
0
MOSCDIS
R/W
0
This bit controls the internal oscillator verification timer
function. If set, the verification timer is enabled and an
interrupt is generated if the timer becomes inoperative.
Otherwise, the verification timer is not enabled.
0
This bit controls the main oscillator verification timer
function. If set, the verification timer is enabled and an
interrupt is generated if the timer becomes inoperative.
Otherwise, the verification timer is not enabled.
0
Internal Oscillator Disable
0: Internal oscillator is enabled.
1: Internal oscillator is disabled.
0
Main Oscillator Disable
0: Main oscillator is enabled.
1: Main oscillator is disabled.
Table 6-3. PLL Mode Control
PWRDN
1
0
OEN
X
0
Mode
Power down
Normal
Table 6-4. Default Crystal Field Values and PLL Programming
Crystal Number
(XTAL Binary Value)
0000-0011
0100
0101
Crystal Frequency (MHz)
reserved
3.579545 MHz
3.6864 MHz
84
October 8, 2006
Preliminary