ADC Control and Status Register B
Name:
ADCSRB
Offset:
0x1C
Reset:
0x00
Access:
-
Bit76543210
ADTS2ADTS1ADTS0
AccessR/WR/WR/W
Reset000

Bits 2:0 – ADTSn: ADC Auto Trigger Source [n = 2:0]

ADC Auto Trigger Source [n = 2:0]

If ADATE in ADCSRA is written to one, the value of these bits selects which source will trigger an ADC conversion. If ADATE is cleared, the ADTS[2:0] settings will have no effect. A conversion will be triggered by the rising edge of the selected Interrupt Flag. Note that switching from a trigger source that is cleared to a trigger source that is set, will generate a positive edge on the trigger signal. If ADEN in ADCSRA is set, this will start a conversion. Switching to Free Running mode (ADTS[2:0]=0) will not cause a trigger event, even if the ADC Interrupt Flag is set.

Table 1. ADC Auto Trigger Source Selection
ADTS[2:0] Trigger Source
000 Free Running mode
001 Analog Comparator
010 External Interrupt Request 0
011 Timer/Counter 0 Compare Match A
100 Timer/Counter 0 Overflow
101 Timer/Counter 0 Compare Match B
110 Pin Change Interrupt 0 Request
111 Timer/Counter 0 Capture Event