Trim and Test Registers - Note
351
SNIU028A – February 2016 – Revised April 2016
Copyright © 2016, Texas Instruments Incorporated
Advanced Power Management Control Functions
9.13 Trim and Test Registers - Note
There are several trim and test registers in the Miscellaneous Analog Control register set.
CAUTION
It is highly recommended that nearly all of the bit-fields in these registers be
untouched by a customer program. There is one exception:
•
For the best clock accuracy over temperature, the HFO_LN_FILTER_EN bit
in the CLKTRIM register should be cleared.
The data sheet specification for clock performance is characterized with this bit
cleared. It is necessary for the customer program to clear this bit, since the
default value is for this bit to be set.
9.13.1 Clock Trim Register (CLKTRIM) (For Factory Test Use Only, Except
HFO_LN_FILTER_EN)
Address FFF7F000
Figure 9-16. Clock Trim Register (CLKTRIM) (For Factory Test Use Only, Except
HFO_LN_FILTER_EN)
14
13
12
11
10
9
8
7
6
5
4
3
2
1
0
HFO_CLK_TRIM
HFO_SEL_
RANGE
HFO_
LN_FIL
TER_E
N
LFO_
DISAB
LE
HFO_THERM_TRIM
HFO_E
NABLE
R/W-011 1000
R/W-10
R/W-1
R/W-0
R/W-011
R/W-1
LEGEND: R/W = Read/Write; R = Read only; -
n
= value after reset
Table 9-21. Clock Trim Register (CLKTRIM) (For Factory Test Use Only, Except
HFO_LN_FILTER_EN) Register Field Descriptions
Bit
Field
Type
Reset
Description
14-8
HFO_CLK_TRIM
R/W
011 1000 High Frequency Oscillator Clock Trim Bits. Register will be programmed during test
and should not be overwritten by firmware
7-6
HFO_SEL_
RANGE
R/W
10
High Frequency Oscillator Range Select Bits. Register will be programmed during
test and should not be overwritten by firmware.
5
HFO_LN_FILTER
_EN
R/W
1
High Frequency Oscillator Low Noise Filter. Register should be cleared by firmware.
4
LFO_DISABLE
R/W
0
Low Frequency Oscillator Disable. Register will be programmed during test and
should not be overwritten by firmware.
0 = Low Frequency Oscillator Enabled (Default)
1 = Low Frequency Oscillator Disabled
3-1
HFO_THERM
_TRIM
R/W
011
High Frequency Oscillator Thermal Coefficient Trim Bits. Register will be
programmed during test and should not be overwritten by firmware
0
HFO_ENABLE
R/W
1
High Frequency Oscillator Enable. Register will be programmed during test and
should not be overwritten by firmware.
0 = High Frequency Oscillator Disabled
1 = High Frequency Oscillator Enabled (Default)