150
8006K–AVR–10/10
ATtiny24/44/84
Bit 6 – ACME: Analog Comparator Multiplexer Enable
Bit 5 – Res: Reserved Bit
This is a reserved bit in ATtiny24/44/84. For compatibility with future devices always write this bit
to zero.
Bit 4 – ADLAR: ADC Left Adjust Result
The ADLAR bit affects the presentation of the ADC conversion result in the ADC Data Register.
Write one to ADLAR to left adjust the result. Otherwise, the result is right adjusted. Changing the
ADLAR bit will affect the ADC Data Register immediately, regardless of any ongoing conver-
Bit 3 – Res: Reserved Bit
This bit is reserved bit in the ATtiny24/44/84 and will always read as what was wrote there.
Bits 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 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
.
16.13.5
DIDR0 – Digital Input Disable Register 0
Bits 7:0 – ADC7D:ADC0D: ADC7:0 Digital Input Disable
When a bit is written logic one, the digital input buffer on the corresponding ADC pin is disabled.
The corresponding PIN register bit will always read as zero when this bit is set. When an analog
signal is applied to the ADC7:0 pin and the digital input from this pin is not needed, this bit
should be written logic one to reduce power consumption in the digital input buffer.
Table 16-7.
ADC Auto Trigger Source Selections
ADTS2
ADTS1
ADTS0
Trigger Source
0
Free Running mode
0
1
Analog Comparator
0
1
0
External Interrupt Request 0
0
1
Timer/Counter0 Compare Match A
1
0
Timer/Counter0 Overflow
1
0
1
Timer/Counter1 Compare Match B
1
0
Timer/Counter1 Overflow
1
Timer/Counter1 Capture Event
Bit
765
432
10
ADC7D
ADC6D
ADC5D
ADC4D
ADC3D
ADC2D
ADC1D
ADC0D
DIDR0
Read/Write
R/W
Initial Value
0