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CH32V003
Reference Manual
V1.3
73
value written after the offset defined in the ADC_IOFRx register, there will be positive and negative cases, so
there are sign bits (SIGNB).
Figure 9-2 Data left alignment
Rule group data register
D11 D10 D9
D8
D7
D6
D5
D4
D4
D2
D1
D0
0
0
0
0
Inject group data register
SIGNB D11 D10 D9
D8
D7
D6
D5
D4
D3
D2
D1
D0
0
0
0
Figure 9-3 Data right alignment
Rule group data register
0
0
0
0
D11 D10 D9
D8
D7
D6
D5
D4
D3
D2
D1
D0
Inject group data register
SIGNB SIGNB SIGNB SIGNB D11 D10 D9 D8 D7 D6 D5 D4 D3 D2 D1 D0
9.2.3 External trigger source
The ADC conversion start event can be triggered by an external event. If the EXTTRIG or JEXTTRIG bits of
the ADC_CTLR2 register are set, the conversion of a rule group or injection group channel can be triggered
by an external event, respectively. In this case, the configuration of EXTSEL[2:0] and JEXTSEL[2:0] bits
determines the external event source for the rule group and injection group.
Table 9-1 External trigger sources for rule group channels
EXTSEL[2:0]
Trigger source
Type
000
TRGO event of timer 1
Internal signal from on-chip
timer
001
CH1 event of timer 1
010
CH2 event of timer 1
011
TRGO event of timer 2
100
CH1 event of timer 2
101
CH2 event of timer 2
110
PD3/PC2 events
From external pins
111
SWSTART software trigger
Software control bits
Table 9-2 External trigger sources for injection group channels
JEXTSEL[2:0]
Trigger source
Type
000
CH3 event of timer 1
Internal signal from on-chip
timer
001
CH4 event of timer 1
010
CH3 event of timer 2
011
CH4 event of timer 2
100
-
101
-
110
PD1/PA2
From external pins
111
JSWSTART software trigger
Software control bits
9.2.4 Conversion mode
Table 9-3 Conversion mode combinations
ADC_CTLR1 and ADC_CTLR2 register control bits
ADC conversion mode
CONT SCAN RDISCEN/IDISCEN IAUTO Start event
0
0
0
0
ADON
position 1
Single single-channel mode: A rule
channel performs a single conversion.
External
trigger
method
Single single-channel mode: A single
conversion is performed on one of the rule
channels or injection channels.
1
0
0
ADON
position 1
or external
Single scan mode: performs a single
conversion of all selected rule group
channels (ADC_RSQRx) or all injection