Analog-to-digital converter (ADC)
RM0090
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DocID018909 Rev 11
Software source trigger events can be generated by setting SWSTART (for regular
conversion) or JSWSTART (for injected conversion) in ADC_CR2.
A regular group conversion can be interrupted by an injected trigger.
Note:
The trigger selection can be changed on the fly. However, when the selection changes,
there is a time frame of 1 APB clock cycle during which the trigger detection is disabled.
This is to avoid spurious detection during transitions.
13.7
Fast conversion mode
It is possible to perform faster conversion by reducing the ADC resolution. The RES bits are
used to select the number of bits available in the data register. The minimum conversion
time for each resolution is then as follows:
•
12 bits: 3 + 12 = 15 ADCCLK cycles
•
10 bits: 3 + 10 = 13 ADCCLK cycles
•
8 bits: 3 + 8 = 11 ADCCLK cycles
•
6 bits: 3 + 6 = 9 ADCCLK cycles
Table 69. External trigger for injected channels
Source
Connection type
JEXTSEL[3:0]
TIM1_CH4 event
Internal signal from on-chip
timers
0000
TIM1_TRGO event
0001
TIM2_CH1 event
0010
TIM2_TRGO event
0011
TIM3_CH2 event
0100
TIM3_CH4 event
0101
TIM4_CH1 event
0110
TIM4_CH2 event
0111
TIM4_CH3 event
1000
TIM4_TRGO event
1001
TIM5_CH4 event
1010
TIM5_TRGO event
1011
TIM8_CH2 event
1100
TIM8_CH3 event
1101
TIM8_CH4 event
1110
EXTI line15
External pin
1111