ATMEGA328P-20PU Atmel, ATMEGA328P-20PU Datasheet - Page 244

• Manufacturer Part Number: ATMEGA328P-20PU
• Manufacturer: Atmel

Specifications of ATMEGA328P-20PU

• Cpu Family: ATmega
• Device Core: AVR
• Device Core Size: 8b
• Frequency (max): 20MHz
• Interface Type: SPI/TWI/USART
• Program Memory Type: Flash
• Program Memory Size: 32KB
• Total Internal Ram Size: 2KB
• # I/os (max): 23
• Number Of Timers - General Purpose: 3
• Operating Supply Voltage (typ): 3.3/5V
• Operating Supply Voltage (max): 5.5V
• Operating Supply Voltage (min): 2.7V
• On-chip Adc: 6-chx10-bit
• Instruction Set Architecture: RISC
• Operating Temp Range: -40C to 85C
• Operating Temperature Classification: Industrial
• Mounting: Through Hole
• Pin Count: 28
• Package Type: PDIP
• Lead Free Status / Rohs Status: Compliant

22.3
22.3.1
22.3.2
8025K–AVR–10/09
Register Description
ADCSRB – ADC Control and Status Register B
ACSR – Analog Comparator Control and Status Register
.
Table 22-1.
• Bit 6 – ACME: Analog Comparator Multiplexer Enable
When this bit is written logic one and the ADC is switched off (ADEN in ADCSRA is zero), the
ADC multiplexer selects the negative input to the Analog Comparator. When this bit is written
logic zero, AIN1 is applied to the negative input of the Analog Comparator. For a detailed
description of this bit, see
• Bit 7 – ACD: Analog Comparator Disable
When this bit is written logic one, the power to the Analog Comparator is switched off. This bit
can be set at any time to turn off the Analog Comparator. This will reduce power consumption in
Active and Idle mode. When changing the ACD bit, the Analog Comparator Interrupt must be
disabled by clearing the ACIE bit in ACSR. Otherwise an interrupt can occur when the bit is
changed.
• Bit 6 – ACBG: Analog Comparator Bandgap Select
When this bit is set, a fixed bandgap reference voltage replaces the positive input to the Analog
Comparator. When this bit is cleared, AIN0 is applied to the positive input of the Analog Compar-
ator. When the bandgap referance is used as input to the Analog Comparator, it will take a
Bit
(0x7B)
Read/Write
Initial Value
Bit
0x30 (0x50)
Read/Write
Initial Value
ACME
0
1
1
1
1
1
1
1
1
1
Analog Comparator Multiplexed Input
ACD
R/W
ADEN
R
7
0
7
–
0
x
1
0
0
0
0
0
0
0
0
ACBG
ACME
R/W
R/W
”Analog Comparator Multiplexed Input” on page
6
0
6
0
MUX2..0
000
001
010
011
100
101
110
111
xxx
xxx
ACO
N/A
R
5
R
5
–
0
Analog Comparator Negative Input
AIN1
AIN1
ADC0
ADC1
ADC2
ADC3
ADC4
ADC5
ADC6
ADC7
R/W
ACI
4
0
R
4
–
0
ACIE
R/W
3
0
R
ATmega48P/88P/168P
3
–
0
ADTS2
ACIC
R/W
R/W
2
0
2
0
ADTS1
ACIS1
R/W
R/W
1
0
1
0
243.
ADTS0
ACIS0
R/W
R/W
0
0
0
0
ADCSRB
ACSR
244