Analog-to-digital converter (ADC) RM0090
275/1422 Doc ID 018909 Rev 4
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.
11.7 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 52. 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