M451
May. 4, 2018
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Rev.2.08
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Enhanced 12-bit Analog-to-Digital Converter (EADC)
6.22
6.22.1 Overview
The M451 series contains one 12-bit successive approximation analog-to-digital converter
(SAR A/D converter) with 16 external input channels and 3 internal channels. The A/D
converter can be started by software trigger, PWM0/1 triggers, timer0~3 overflow pulse
triggers, ADINT0, ADINT1 interrupt EOC (End of conversion) pulse trigger and external pin
(STADC) input signal.
6.22.2 Features
Analog input voltage range: 0~V
REF
(Max to AV
DD
).
Reference voltage from V
REF
pin.
12-bit resolution and 10-bit accuracy is guaranteed.
Up to 16 single-end analog external input channels or 8 pair differential analog input
channels.
3 internal channels, they are band-gap voltage (V
BG
), temperature sensor (V
TEMP
), and
Battery power (V
BAT
)
Four ADC interrupts (ADINT0~3) with individual interrupt vector addresses.
Maximum ADC clock frequency is 20 MHz.
Up to 1 Msps conversion rate.
Configurable ADC internal sampling time.
Up to 19 sample modules
–
Each of sample module 0~15 which is configurable for ADC converter channel
EADC_CH0~15 and trigger source.
–
Sample module 16~18 is fixed for ADC channel 16, 17, 18 input sources as band-gap
voltage, temperature sensor, and battery power (V
BAT
).
–
Double buffer for sample module 0~3
–
Configurable sampling time for each sample module.
–
Conversion results are held in 19 data registers with valid and overrun indicators.
An A/D conversion can be started by:
–
Write 1 to SWTRGn (EADC_SWTRG[n] , n = 0~18)
–
External pin STADC
–
Timer0~3 overflow pulse triggers
–
ADINT0 and ADINT1 interrupt EOC (End of conversion) pulse triggers
–
PWM triggers
Supports PDMA transfer
