Datasheet

221

2466T–AVR–07/10

ATmega16(L)

Special FunctionIO

• Bit 7:5 – 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 trig-

ger 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

• Bit 4 – Res: Reserved Bit

This bit is reserved for future use. To ensure compatibility with future devices, this bit must be

written to zero when SFIOR is written.

Bit 76543210

ADTS2 ADTS1 ADTS0 –

ACME PUD PSR2 PSR10 SFIOR

Read/Write R/W R/W R/W R R/W R/W R/W R/W

Initial Value 0 0 0 0 0 0 0 0

Table 86. ADC Auto Trigger Source Selections

ADTS2 ADTS1 ADTS0 Trigger Source

0 0 0 Free Running mode

0 0 1 Analog Comparator

0 1 0 External Interrupt Request 0

0 1 1 Timer/Counter0 Compare Match

1 0 0 Timer/Counter0 Overflow

1 0 1 Timer/Counter1 Compare Match B

1 1 0 Timer/Counter1 Overflow

1 1 1 Timer/Counter1 Capture Event