Texas Instruments UCD3138 Technical Reference Manual page 134

Front End Control Registers
Table 3-11. EADC Control Register (EADCCTRL) Register Field Descriptions (continued)
Bit Field
14 AUTO_GAIN
_SHIFT_MODE
13 AUTO_GAIN
_SHIFT_EN
12 AVG_WEIGHT
_EN
11 AVG_SPATIAL
_EN
10-9 AVG_MODE_SEL
8-6 EADC_MODE
5-4 AFE_GAIN
3 SCFE_GAIN
_FILTER_SEL
2 SCFE_CLK_DIV_2 R/W
1 SCFE_ENA
0 EADC_ENA
134
Front End
Type Reset
R/W 0
Configures Automatic Gain Shifting mode
0 = Fixed mode, gain shifting dependent on saturation of EADC for decreasing gain
and less than 1/4 of dynamic range for increasing gain (Default)
1 = NL mode, gain shifting dependent on Non-Linear limit thresholds
R/W 0
Enables Automatic Gain Shifting mode
0 = Automatic Gain Shifting Mode disabled (Default)
1 = Automatic Gain Shifting Mode enabled
R/W 0
Enables weighted averaging in EADC averaging mode, only applicable in 4x and 8x
averaging mode. For 4x averaging, two oldest samples are each weighted by 1/8,
the next oldest sample has a weight of ¼ and the newest sample is weighted by ½.
For 8x averaging, the four oldest samples are each weighted by 1/16, the next 2
oldest samples are weighted by 1/8, and the two newest samples are weighted by
1/4.
0 = Weighted averaging disabled (Default)
1 = Weighted averaging enabled
R/W 0
Enables spatial mode in EADC averaging mode
0 = Consecutive EADC samples averaged based on every received sample trigger
from DPWM modules (Default)
1 = EADC samples averaged based on received sample triggers from DPWM
modules. 2 sample triggers required for a single averaged sample to filter. 4 sample
triggers required for a single averaged sample to filter module
R/W 00
Averaging Mode Configuration
0 = 2x Averaging (Default)
1 = 4x Averaging
2 = 8x Averaging
R/W 000
Selects EADC Mode Operation
0 = Standard mode, EADC samples based on sample triggers from DPWM module
(Default)
1 = Averaging Mode, configured by AVG_MODE_SEL 2 = Non-continuous SAR
Mode 3 = Continuous SAR Mode
4 = Reserved
5 = Peak Current Mode
6 = Constant Power/Constant Current Control Mode (CPCC module controls
switching between Standard Mode and Non-Continuous SAR Mode)
7 = Constant Power/Constant Current Control 2 Mode (CPCC module controls
switching between Standard mode and Continuous SAR Mode)
R/W 11
AFE Front End Gain Setting
0 = 1x Gain, 8mV/LSB
1 = 2x Gain, 4mV/LSB
2 = 4x Gain, 2mV/LSB
3 = 8x Gain, 1mV/LSB (Default)
R/W 1
Switched Cap Noise Filter Enable
0 = Disables Switch Cap Noise Filter
1 = Enables Switch Cap Noise Filter (Default)
1
Switched Cap Front End Clock Divider Select
0 = Switch Cap Period divide by 1 (128 ns nominal sample period)
1 = Switch Cap Period divide by 2 (Default – 64 ns nominal sample period)
R/W 1
Switch Cap Front Enable
0 = Disables Switch Cap Front End logic
1 = Enables Switch Cap Front End logic (Default)
R/W 1
EADC Enable
0 = Disables EADC
1 = Enables EADC (Default)
Copyright © 2016, Texas Instruments Incorporated
Description
SNIU028A – February 2016 – Revised April 2016
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