AT90USB647-MU Atmel, AT90USB647-MU Datasheet - Page 312

• Manufacturer Part Number: AT90USB647-MU
• Description: MCU, 8BIT, 64K FLASH, USB, 64QFN
• Manufacturer: Atmel

Specifications of AT90USB647-MU

• Controller Family/series: AT90
• No. Of I/o's: 48
• Eeprom Memory Size: 2KB
• Ram Memory Size: 4KB
• Cpu Speed: 16MHz
• No. Of: RoHS Compliant
• Core Size: 8bit
• Program Memory Size: 64KB
• Oscillator Type: External, Internal
• Package: 64QFN EP
• Device Core: AVR
• Family Name: AT90
• Maximum Speed: 20 MHz
• Ram Size: 4 KB
• Operating Supply Voltage: 3.3|5 V
• Data Bus Width: 8 Bit
• Program Memory Type: Flash
• Number Of Programmable I/os: 48
• Interface Type: SPI/TWI/USART/USB
• On-chip Adc: 8-chx10-bit
• Operating Temperature: -40 to 85 °C
• Number Of Timers: 4
• Lead Free Status / Rohs Status: Details

24.1
24.1.1
312
Analog Comparator Multiplexed Input
AT90USB64/128
Digital Input Disable Register 1 – DIDR1
It is possible to select any of the ADC7..0 pins to replace the negative input to the Analog Com-
parator. The ADC multiplexer is used to select this input, and consequently, the ADC must be
switched off to utilize this feature. If the Analog Comparator Multiplexer Enable bit (ACME in
ADCSRB) is set and the ADC is switched off (ADEN in ADCSRA is zero), and MUX2..0 in
ADMUX select the input pin to replace the negative input to the Analog Comparator, as shown in
Table
log Comparator.
Table 24-2.
• Bit 1, 0 – AIN1D, AIN0D: AIN1, AIN0 Digital Input Disable
When this bit is written logic one, the digital input buffer on the AIN1/0 pin is disabled. The corre-
sponding PIN Register bit will always read as zero when this bit is set. When an analog signal is
applied to the AIN1/0 pin and the digital input from this pin is not needed, this bit should be writ-
ten logic one to reduce power consumption in the digital input buffer.
Bit
Read/Write
Initial Value
ACME
0
1
1
1
1
1
1
1
1
1
24-2. If ACME is cleared or ADEN is set, AIN1 is applied to the negative input to the Ana-
ADEN
7
–
R
0
Analog Comparator Mulitiplexed Input
x
1
0
0
0
0
0
0
0
0
6
–
R
0
MUX2..0
000
001
010
011
100
101
110
111
xxx
xxx
5
–
R
0
Analog Comparator Negative Input
AIN1
AIN1
ADC0
ADC1
ADC2
ADC3
ADC4
ADC5
ADC6
ADC7
4
–
R
0
3
–
R
0
2
–
R
0
1
AIN1D
R/W
0
0
AIN0D
R/W
0
DIDR1
7593K–AVR–11/09