TM4C123GH6PM Datasheet, PDF (263/1409 Pages) Texas Instruments – Tiva Microcontroller

Tiva^™ TM4C123GH6PM Microcontroller
Register 11: 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.
Main Oscillator Control (MOSCCTL)
Base 0x400F.E000
Offset 0x07C
Type RW, reset 0x0000.0000
31
30
29
28
27
26
25
24
23
22
21
20
19
18
17
16
reserved
Type RO
RO
RO
RO
RO
RO
RO
RO
RO
RO
RO
RO
RO
RO
RO
RO
Reset
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
0
reserved
NOXTAL MOSCIM CVAL
Type RO
RO
RO
RO
RO
RO
RO
RO
RO
RO
RO
RO
RO
RW
RW
RW
Reset
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
Bit/Field
31:3
2
Name
reserved
NOXTAL
Type
Reset Description
RO 0x0000.000 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.
RW
0
No Crystal Connected
Value Description
0 This bit should be cleared when a crystal or oscillator is
connected to the OSC0 and OSC1 inputs, regardless of whether
or not the MOSC is used or powered down.
1 This bit should be set when a crystal or external oscillator is not
connected to the OSC0 and OSC1 inputs to reduce power
consumption.
1
MOSCIM
RW
0
MOSC Failure Action
Value Description
0 If the MOSC fails, a MOSC failure reset is generated and reboots
to the NMI handler.
1 If the MOSC fails, an interrupt is generated as indicated by the
MOFRIS bit in the RIS register..
Regardless of the action taken, if the MOSC fails, the oscillator source
is switched to the PIOSC automatically.
0
CVAL
RW
0
Clock Validation for MOSC
Value Description
0 The MOSC monitor circuit is disabled.
1 The MOSC monitor circuit is enabled.
June 12, 2014
263
Texas Instruments-Production Data