SN32F280 Series
32-Bit Cortex-M0 Micro-Controller
SONiX TECHNOLOGY CO., LTD
Page 96
Version 1.1
7.5 ADC REGISTERS
Base Address: 0x4002 6000
7.5.1 ADC Management register (ADC_ADM)
Address Offset: 0x00
Note:
1. When ADC is enabled (ADENB=1) and global channel is enabled (GCHS=1), the ADC shared pins
transfers to ADC purpose and disable GPIO function and disable pull-up/pull-down resistor by HW
automatically, t
he P2.n/AINn’s digital I/O function including pull-up is isolated.
2. When ADC is disabled (ADENB=0) or global channel is disabled (GCHS=0) , the ADC pins returns to
last GPIO status.
3. If P2.0 is used as external reference voltage input pin, users should set P2.0 as input mode inactive
(no pull-down/up resistor enabled, Schmitt trigger disabled.
4. If AIN16 channel is selected as internal 2V/3V/4.5V input channel, there is no any input pin from
outside. In this time ADC reference voltage must be internal VDD and External voltage, Not internal
2V/3V/4.5V.
5. The GPIO mode of ADC input channels used must be set as input mode and inactive (no pull-
down/
pull-up resistor enabled, Schmitt trigger disabled, Data register keep low) with
GPIO2_MODE and GPIO2_CFG register by program.
Bit
Name
Description
Attribute
Reset
31:17
Reserved
R
0
16:14
VHS[2:0]
Internal reference voltage level selection.
000: Internal 2.0V as ADC internal reference high voltage
001: Internal 3.0V as ADC internal reference high voltage
010: Internal 4.5V as ADC internal reference high voltage
011: Reserved
100: VDD as ADC internal reference high voltage, Internal 2.0V as AIN16
101: VDD as ADC internal reference high voltage, Internal 3.0V as AIN16
110: VDD as ADC internal reference high voltage, Internal 4.5V as AIN16
111: VDD as ADC internal reference high voltage
R/W
000b
13
AVREFHSEL
ADC high reference voltage source select bit
0: Internal reference voltage. (P2.0 is GPIO or AIN0 pin)
1: Enable external reference voltage from P2.0
R/W
0
12
ADENB
ADC Enable bit. In power saving mode, disable ADC to reduce power
consumption.
0: Disable
1: Enable
R/W
0
11:9
ADCKS[2:0]
ADC Clock source divider
000: ADC_PCLK / 1
001: ADC_PCLK / 2
010: ADC_PCLK / 4
011: ADC_PCLK / 8
101: ADC_PCLK / 16
110: ADC_PCLK / 32
Other: Reversed
R/W
0
8
ADLEN
ADC resolution control bit.
0: 8-bit ADC.
1:12-bit ADC.
R/W
0
7
ADS
ADC start control bit.
0: ADC converting stops.
1: Start to execute ADC converting. ADS is cleared when the end of ADC
converting automatically.
R/W
0
6
EOC
ADC status bit. Indicates ADC processing status immediately and is
cleared when ADS = 1.
0: ADC progressing.
1: End of converting and reset ADS bit.
R/W
0