ATMEGA644PV ATMEL [ATMEL Corporation], ATMEGA644PV Datasheet - Page 257

• Manufacturer Part Number: ATMEGA644PV
• Description: 8-bit Microcontroller with 16/32/64K Bytes In-System Programmable Flash
• Manufacturer: ATMEL [ATMEL Corporation]

21.9.5
8011D–AVR–02/07
DIDR0 – Digital Input Disable Register 0
• Bit 7, 5:3 – Res: Reserved Bits
These bits are reserved for future use in the ATmega164P/324P/644P. For ensuring compability
with future devices, these bits must be written 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 ADTS[2:0] settings will have no effect. A conver-
sion 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 21-6.
• Bit 7..0 – ADC7D..ADC0D: ADC7..0 Digital Input Disable
When this bit is written logic one, the digital input buffer on the corresponding ADC pin is dis-
abled. 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.
Bit
(0x7E)
Read/Write
Initial Value
ADTS2
0
0
0
0
1
1
1
1
ADC7D
ADC Auto Trigger Source Selections
R/W
7
0
ADTS1
0
0
1
1
0
0
1
1
ADC6D
R/W
6
0
ADC5D
ADTS0
R/W
5
0
0
1
0
1
0
1
0
1
ADC4D
R/W
4
0
Trigger Source
Free Running mode
Analog Comparator
External Interrupt Request 0
Timer/Counter0 Compare Match
Timer/Counter0 Overflow
Timer/Counter1 Compare Match B
Timer/Counter1 Overflow
Timer/Counter1 Capture Event
ATmega164P/324P/644P
ADC3D
R/W
3
0
ADC2D
R/W
2
0
ADC1D
R/W
1
0
ADC0D
R/W
0
0
.
DIDR0
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