ATMEGA2561V ATMEL [ATMEL Corporation], ATMEGA2561V Datasheet - Page 299

• Manufacturer Part Number: ATMEGA2561V
• Description: 8-bit Microcontroller with 64K/128K/256K Bytes In-System Programmable Flash
• Manufacturer: ATMEL [ATMEL Corporation]

ADCSRB – ADC Control and
Status Register B
2549K–AVR–01/07
• Bit 7 – Res: Reserved Bit
This bit is reserved for future use. To ensure compatibility with future devices, this bit
must be written to zero when ADCSRB is written.
• Bit 2:0 – ADTS2:0: ADC Auto Trigger Source
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 ADTS2:0 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 trig-
ger event, even if the ADC Interrupt Flag is set
Table 131. ADC Auto Trigger Source Selections
Note:
Bit
(0x7B)
Read/Write
Initial Value
ADTS2
0
0
0
0
1
1
1
1
Free running mode cannot be used for differential channels. (See chapter “Differential
Channels” on page 285)
R
7
–
0
ADTS1
ACME
R/W
ATmega640/1280/1281/2560/2561
6
0
0
0
1
1
0
0
1
1
R
5
–
0
ADTS0
R
4
–
0
0
1
0
1
0
1
0
1
.
MUX5
R/W
3
0
Trigger Source
Free Running mode
Analog Comparator
External Interrupt Request 0
Timer/Counter0 Compare Match A
Timer/Counter0 Overflow
Timer/Counter1 Compare Match B
Timer/Counter1 Overflow
Timer/Counter1 Capture Event
ADTS2
R/W
2
0
ADTS1
R/W
1
0
ADTS0
R/W
0
0
ADCSRB
299