Fast Conversion Mode; Table 78. External Trigger For Injected Channels - ST STM32F423 Reference Manual

Analog-to-digital converter (ADC)
Table 78
TIM1_CH4 event
TIM1_TRGO event
TIM2_CH1 event
TIM2_TRGO event
TIM3_CH2 event
TIM3_CH4 event
TIM4_CH1 event
TIM4_CH2 event
TIM4_CH3 event
TIM4_TRGO event
TIM5_CH4 event
TIM5_TRGO event
TIM8_CH2 event
TIM8_CH3 event
TIM8_CH4 event
EXTI line15
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
346/1324
gives the possible external trigger for injected conversion.

Table 78. External trigger for injected channels

Source
Internal signal from on-chip timers
External pin
Connection type
RM0430 Rev 8
RM0430
JEXTSEL[3:0]
0000
0001
0010
0011
0100
0101
0110
0111
1000
1001
1010
1011
1100
1101
1110
1111