Register 10: Main Oscillator Control (MOSCCTL), offset 0x07C
This register provides control over the features of the main oscillator, including the ability to enable
the MOSC clock verification circuit, what action to take when the MOSC fails, and whether or not a
crystal is connected. When enabled, this circuit monitors the frequency of the MOSC to verify that
the oscillator is operating within specified limits. If the clock goes invalid after being enabled, the
microcontroller issues a power-on reset and reboots to the NMI handler or generates an interrupt.
Note:
If the MOSC is chosen as the clock to the Ethernet PHY then software has to enable the
MOSC before enabling the Ethernet PHY by setting the
P0
bit in the
PCEPHY
.
Main Oscillator Control (MOSCCTL)
Base 0x400F.E000
Offset 0x07C
Type RW, reset 0x0000.000C
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
reserved
RO
RO
RO
RO
RO
RO
RO
RO
RO
RO
RO
RO
RO
RO
RO
RO
Type
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
Reset
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
CVAL
MOSCIM
NOXTAL
PWRDN
OSCRNG
reserved
RW
RW
RW
RW
RW
RO
RO
RO
RO
RO
RO
RO
RO
RO
RO
RO
Type
0
0
1
1
0
0
0
0
0
0
0
0
0
0
0
0
Reset
Description
Reset
Type
Name
Bit/Field
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.
0x0000.000
RO
reserved
31:5
Oscillator Range
Specifies the frequency range of operation of the oscillator.
Description
Value
Low Frequency Range
0
High Frequency Range (equal to or greater than 10 MHz).
1
0
RW
OSCRNG
4
Power Down
Provides user control over powering down the main oscillator circuit.
Description
Value
Power to main oscillator circuit is enabled.
0
Main Oscillator circuit is powered down.
1
Note:
This bit should be cleared when using a crystal and set for
single-ended mode.
1
RW
PWRDN
3
273
June 18, 2014
Texas Instruments-Production Data
Tiva
™
TM4C1294NCPDT Microcontroller