ATmega1281R231 Atmel Corporation, ATmega1281R231 Datasheet - Page 294

• Manufacturer Part Number: ATmega1281R231
• Manufacturer: Atmel Corporation

Specifications of ATmega1281R231

• Flash (kbytes): 128 Kbytes
• Max. Operating Frequency: 16 MHz
• Max I/o Pins: 54
• Spi: 3
• Twi (i2c): 1
• Uart: 2
• Adc Channels: 8
• Adc Resolution (bits): 10
• Adc Speed (ksps): 15
• Analog Comparators: 1
• Crypto Engine: AES
• Sram (kbytes): 8
• Eeprom (bytes): 4096
• Operating Voltage (vcc): 1.8 to 3.6
• Timers: 6
• Frequency Band: 2.4 GHz
• Max Data Rate (mb/s): 2
• Antenna Diversity: Yes
• External Pa Control: Yes
• Power Output (dbm): 3
• Receiver Sensitivity (dbm): -101
• Receive Current Consumption (ma): 13.2
• Transmit Current Consumption (ma): 14.4
• Link Budget (dbm): 104

26.8.4
26.8.4.1
26.8.4.2
26.8.5
2549N–AVR–05/11
ADCL and ADCH – The ADC Data Register
ADCSRB – ADC Control and Status Register B
ADLAR = 0
ADLAR = 1
When an ADC conversion is complete, the result is found in these two registers. If differential
channels are used, the result is presented in two’s complement form.
When ADCL is read, the ADC Data Register is not updated until ADCH is read. Consequently, if
the result is left adjusted and no more than 8-bit precision (7 bit + sign bit for differential input
channels) is required, it is sufficient to read ADCH. Otherwise, ADCL must be read first, then
ADCH.
The ADLAR bit in ADMUX, and the MUXn bits in ADMUX affect the way the result is read from
the registers. If ADLAR is set, the result is left adjusted. If ADLAR is cleared (default), the result
is right adjusted.
• ADC9:0: ADC Conversion Result
These bits represent the result from the conversion, as detailed in
page
• Bit 7 – Res: Reserved Bit
This bit is reserved for future use. To ensure compatibility with future devices, this bit must be
written to 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 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-
Bit
(0x79)
(0x78)
Read/Write
Initial Value
Bit
(0x79)
(0x78)
Read/Write
Initial Value
Bit
(0x7B)
Read/Write
Initial Value
288.
ADC7
ADC9
ADC1
15
15
R
R
R
R
–
7
0
0
7
0
0
R
7
–
0
ADC6
ADC8
ADC0
ACME
R/W
14
14
R
R
R
R
–
6
0
0
6
0
0
6
0
ATmega640/1280/1281/2560/2561
ADC5
ADC7
13
13
R
R
R
R
–
5
0
0
–
5
0
0
R
5
–
0
ADC4
ADC6
12
12
R
R
R
R
–
4
0
0
–
4
0
0
R
4
–
0
ADC3
ADC5
MUX5
R/W
11
11
R
R
R
R
–
3
0
0
–
3
0
0
3
0
ADTS2
ADC2
ADC4
R/W
10
10
R
R
R
R
–
2
0
0
–
2
0
0
2
0
“ADC Conversion Result” on
ADTS1
ADC9
ADC1
ADC3
R/W
R
R
R
R
9
1
0
0
9
–
1
0
0
1
0
ADTS0
ADC8
ADC0
ADC2
R/W
R
R
R
R
8
0
0
0
8
–
0
0
0
0
0
ADCSRB
ADCH
ADCH
ADCL
ADCL
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