Datasheet

560
15.4.8 Conversion Start by External Input
A/D conversions can be started by trigger signals generated by timer conversion start triggers or
ADTRG inputs. When a trigger signal designated by the TRGS1 and TRGS0 bits of the ADCR
occurs, the ADST bit of the ADCSR is set to 1 and A/D conversion is started.
The other operations are the same as when the ADST bit is set to 1 by software. Figure 15.12
shows an example of the timing when the ADST bit is set by an external input.
ADDRB
ADDRA
ADST
ADDRD
ADDRC
ADF
Set
ADTRG
(external
trigger)
Channel 0
Channel 1
Channel 2
Channel 3
Sam-
pling 1
A/D
conver-
sion 1
Conver-
sion
standby
Conversion
standby
Conversion standby
Conversion standby
Conversion standby
Conversion result 1
Figure 15.12 Conversion Start by ADTRG Conversion Start Trigger