LM3S5G51 Datasheet, PDF (229/1266 Pages) Texas Instruments – Stellaris® LM3S5G51 Microcontroller

Stellaris^® LM3S5G51 Microcontroller
Register 13: Precision Internal Oscillator Calibration (PIOSCCAL), offset 0x150
This register provides the ability to update or recalibrate the precision internal oscillator. Note that
a 32.768-kHz oscillator must be used as the Hibernation module clock source for the user to be
able to calibrate the PIOSC.
Precision Internal Oscillator Calibration (PIOSCCAL)
Base 0x400F.E000
Offset 0x150
Type R/W, reset 0x0000.0000
31
30
29
28
27
26
25
24
23
22
21
20
19
18
17
16
UTEN
reserved
Type R/W
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
CAL UPDATE reserved
UT
Type RO
RO
RO
RO
RO
RO
R/W
R/W
RO
R/W
R/W
R/W
R/W
R/W
R/W
R/W
Reset
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
Bit/Field
31
Name
UTEN
Type
R/W
Reset
0
Description
Use User Trim Value
Value Description
1 The trim value in bits[6:0] of this register are used for any update
trim operation.
0 The factory calibration value is used for an update trim operation.
30:10
9
8
7
reserved
CAL
UPDATE
reserved
RO
0x0000 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.
R/W
0
Start Calibration
Value Description
1 Starts a new calibration of the PIOSC. Results are in the
PIOSCSTAT register. The resulting trim value from the operation
is active in the PIOSC after the calibration completes. The result
overrides any previous update trim operation whether the
calibration passes or fails.
0 No action.
This bit is auto-cleared after it is set.
R/W
0
Update Trim
Value Description
1 Updates the PIOSC trim value with the UT bit or the DT bit in
the PIOSCSTAT register. Used with UTEN.
0 No action.
This bit is auto-cleared after the update.
RO
0
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.
January 23, 2012
229
Texas Instruments-Production Data