User Manual
Apollo3 Blue Datasheet
DS-A3-0p9p1 Page 766 of 909 2019 Ambiq Micro, Inc.
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19.2.2 VCOMP Registers
19.2.2.1 CFG Register
Configuration Register
OFFSET: 0x00000000
INSTANCE 0 ADDRESS: 0x4000C000
The Voltage Comparator Configuration Register contains the software control for selecting beween the 4
options for the positive input as well as the multiple options for the reference input.
Table 1129: CFG Register
3
1
3
0
2
9
2
8
2
7
2
6
2
5
2
4
2
3
2
2
2
1
2
0
1
9
1
8
1
7
1
6
1
5
1
4
1
3
1
2
1
1
1
0
0
9
0
8
0
7
0
6
0
5
0
4
0
3
0
2
0
1
0
0
RSVD LVLSEL RSVD
NSEL
RSVD
PSEL
Table 1130: CFG Register Bits
Bit Name Reset RW Description
31:20 RSVD 0x0 RO
This bitfield is reserved for future use.
19:16 LVLSEL 0x0 RW
When the reference input NSEL is set to NSEL_DAC, this bitfield selects the
voltage level for the negative input to the comparator.
0P58V = 0x0 - Set Reference input to 0.58 Volts.
0P77V = 0x1 - Set Reference input to 0.77 Volts.
0P97V = 0x2 - Set Reference input to 0.97 Volts.
1P16V = 0x3 - Set Reference input to 1.16 Volts.
1P35V = 0x4 - Set Reference input to 1.35 Volts.
1P55V = 0x5 - Set Reference input to 1.55 Volts.
1P74V = 0x6 - Set Reference input to 1.74 Volts.
1P93V = 0x7 - Set Reference input to 1.93 Volts.
2P13V = 0x8 - Set Reference input to 2.13 Volts.
2P32V = 0x9 - Set Reference input to 2.32 Volts.
2P51V = 0xA - Set Reference input to 2.51 Volts.
2P71V = 0xB - Set Reference input to 2.71 Volts.
2P90V = 0xC - Set Reference input to 2.90 Volts.
3P09V = 0xD - Set Reference input to 3.09 Volts.
3P29V = 0xE - Set Reference input to 3.29 Volts.
3P48V = 0xF - Set Reference input to 3.48 Volts.
15:10 RSVD 0x0 RO
This bitfield is reserved for future use.
9:8 NSEL 0x0 RW
This bitfield selects the negative input to the comparator.
VREFEXT1 = 0x0 - Use external reference 1 for reference input.
VREFEXT2 = 0x1 - Use external reference 2 for reference input.
VREFEXT3 = 0x2 - Use external reference 3 for reference input.
DAC = 0x3 - Use DAC output selected by LVLSEL for reference input.
7:2 RSVD 0x0 RO
This bitfield is reserved for future use.