AT90CAN128-16AE ATMEL Corporation, AT90CAN128-16AE Datasheet - Page 277

• Manufacturer Part Number: AT90CAN128-16AE
• Description: 8-bit Avr Microcontroller With 128K Bytes of Isp Flash And CAN Controller.flash (Kbytes) 128 Vcc (V) 2.7-5.5 EEPROM (Kbytes) 4 SRAM (bytes) 4K CAN (mess. Obj.) 15
• Manufacturer: ATMEL Corporation

ADC Register Description
ADC Multiplexer Selection
Register – ADMUX
4250C–CAN–03/04
• Bit 7:6 – REFS1:0: Reference Selection Bits
These bits select the voltage reference for the ADC, as shown in Table 100. If these bits
are changed during a conversion, the change will not go in effect until this conversion is
complete (ADIF in ADCSRA is set). The internal voltage reference options may not be
used if an external reference voltage is being applied to the AREF pin.
Table 100. Voltage Reference Selections for ADC
•
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 conversions. For a complete description of this bit, see “The
ADC Data Register – ADCL and ADCH” on page 280.
• Bits 4:0 – MUX4:0: Analog Channel Selection Bits
The value of these bits selects which combination of analog inputs are connected to the
ADC. These bits also select the gain for the differential channels. See Table 101 for
details. If these bits are changed during a conversion, the change will not go in effect
until this conversion is complete (ADIF in ADCSRA is set).
Bit
Read/Write
Initial Value
REFS1
Bit 5 – ADLAR: ADC Left Adjust Result
0
0
1
1
REFS0
REFS1
0
1
0
1
R/W
7
0
Voltage Reference Selection
AREF, Internal Vref turned off
AV
Reserved
Internal 2.56V Voltage Reference with external capacitor on AREF pin
REFS0
R/W
CC
6
0
with external capacitor on AREF pin
ADLAR
R/W
5
0
MUX4
R/W
4
0
MUX3
R/W
3
0
MUX2
R/W
2
0
AT90CAN128
MUX1
R/W
1
0
MUX0
R/W
0
0
ADMUX
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