Transcript MSP432 Online Training Series - Part 6x

MSP432™ MCUs Training
Part 6: Analog Peripherals
ADC14
COMP_E
REF
1
+
ADC14 | Overview
• 14-bit Accuracy
– INL <= +/- 2 LSB;
– DNL <= +/- 1 LSB
– ENOB 13-bit
• 32-input channels
• Single-ended & differential Inputs
– High interrupt
– Low interrupt
– In [Between] interrupt
• Separate internal channels for
AVcc and TempSensor
• Ultra Low current consumption
– Single ended 210uA @ 1.8V, 1Msps
– Differential 260uA @ 1.8V, 1Msps
P
M
u
l
t
i
p
l
e
x
e
r
Sample / Hold
• 2 Window comparators
REF Voltage Select
I/
A/D
Converter
ADC14 Memory Registers
Clock
ADC14 | New Features
= New Feature
Internal
Channel
Mapping
= Enhanced
Feature
Reference
external
external
internal
0
1
external
internal
0
1
32-input channels
internal
0
1
Differential
Measurement
14-bit ADC
Core
...
Enhanced
ADC
Memory
Enhanced
Clock
14-bit
Window
Comparator
Interrupt
3
ADC14 | Window Comparator
Internal
• Configurable
input threshold levels
= New Feature
Channel
Mapping
• Conversion results automatically
ADC14HI
compared against the thresholds Reference
threshold
external
0
1
32-input channels
internal
• Hi, Lo, and In interrupts indicate
which range the result falls in
external
Differentia
14-bit ADC
0
internal
ADC14LO
l
1
• Same thresholds Measurement
shared among all Core
threshold
channels
external
internal
0
1
...
• Useful for low power because
device can stay in sleep mode until
result falls in window
Enhanced
ADC
Memory
= Enhanced
Feature
Set ADC14HIIFG
Set ADC14INIFG
Enhanced
Clock
Set ADC14LOIFG
14-bit
Window
Comparato
r
Interrupt
4
ADC14 | Window Comparator Example
Set ADC14HIIFG
ADC14HI threshold
Set ADC14INIFG
ADC14LO threshold
Set ADC14LOIFG
5
ADC14 | Differential Measurement
•
Internal
Channel
Combine
Mapping
= New Feature
= Enhanced
input channels to create differential input channels
Feature
• ADC will measure the difference between two channels and
Reference
0
store
this
value
in
the
ADC14MEMx
register
internal
external
external
internal
VREF+
external
internal
0
1
A1
0
1
...
A2
32-input channels
1
Differentia
Differential
l
Measurement
Measurement
14-bit ADC
Core
Enhanced
Clock
A1 voltage
∆
Difference
A2 voltage
Enhanced
ADC
Memory
ADC14MEMx
Register
14-bit
Window
Comparator
Interrupt
VREF6
ADC14 | Internal Channel Mapping
= New Feature
Internal
Channel
Mapping
= Enhanced
Feature
external
external
internal
0
1
external
internal
0
1
32-input channels
internal
0
1
• A26-31 can map Reference
to either an External Input
or Internal ADC input
Differentia
14-bit ADC
Enhanced
• Internal
the temperature
l inputs include
Core
Clock
Measurement
sensor and battery monitor
...
• See the device datasheet to see what
internal inputs are available
on what 14-bit
Enhanced
Window
channels – varies by device
ADC
Memory
Interrupt
Comparato
r
7
ADC14 | Other enhancements
Internal
Channel
Mapping
= New Feature
Some ADC12 implementations
external
internal
0
1
external
internal
0
1
32-input channels
internal
channels
More Reference
clock sources, including:
MODOSC = 25MHz
SYSOSC = 5MHz
external
0
1
= Enhanced
haveFeature
up to 16
Differential
Measurement
14-bit ADC
Core
Enhanced
Clock
32 ADC14MEMx registers
...
Enhanced
Enhanced
ADC
ADC
Memory
Memory
14-bit
Window
Comparator
Interrupt
8
Comp_E | Overview
• Interrupt driven for low power
• Uses the REF module like ADC14
• Up to 15 external input channels
• Ultra-low-power comparator mode
• Software selectable RC filter
• Selectable reference voltage generator
• Voltage Hysteresis generator
• Output internally connected to Timer A capture input (for event capture
& capacitive touch implementations)
9
REF | Reference Module
• Generates voltage references for analog modules
– 1.2V, 1.45V, 2.5V
• Available on output pin
• Scale-able power options
– Static mode for high precision outputs
– Sampled mode for low-power operations
• Two operation modes:
– Continuous Mode: reference output continuously on
– Burst Mode: reference output on only during ADC conversions
• Two buffers to throttle power consumption:
– Large buffer for continuous mode or output VREF to pin
– Small buffer for burst mode
• Provides temp sensor channel for ADC
– Option to disable to minimize power
10