ATMEGA644P-20PU Atmel, ATMEGA644P-20PU Datasheet - Page 255
ATMEGA644P-20PU
Manufacturer Part Number
ATMEGA644P-20PU
Description
IC MCU AVR 64K FLASH 40-DIP
Manufacturer
Atmel
Series
AVR® ATmegar
Specifications of ATMEGA644P-20PU
Core Processor
AVR
Core Size
8-Bit
Speed
20MHz
Connectivity
I²C, SPI, UART/USART
Peripherals
Brown-out Detect/Reset, POR, PWM, WDT
Number Of I /o
32
Program Memory Size
64KB (32K x 16)
Program Memory Type
FLASH
Eeprom Size
2K x 8
Ram Size
4K x 8
Voltage - Supply (vcc/vdd)
2.7 V ~ 5.5 V
Data Converters
A/D 8x10b
Oscillator Type
Internal
Operating Temperature
-40°C ~ 85°C
Package / Case
40-DIP (0.600", 15.24mm)
Processor Series
ATMEGA64x
Core
AVR8
Data Bus Width
8 bit
Data Ram Size
4 KB
Interface Type
2-Wire/JTAG/SPI/USART
Maximum Clock Frequency
20 MHz
Number Of Programmable I/os
32
Number Of Timers
3
Maximum Operating Temperature
+ 85 C
Mounting Style
Through Hole
3rd Party Development Tools
EWAVR, EWAVR-BL
Development Tools By Supplier
ATAVRDRAGON, ATSTK500, ATSTK600, ATAVRISP2, ATAVRONEKIT
Minimum Operating Temperature
- 40 C
On-chip Adc
8-ch x 10-bit
For Use With
ATSTK600-TQFP44 - STK600 SOCKET/ADAPTER 44-TQFPATSTK600 - DEV KIT FOR AVR/AVR32770-1007 - ISP 4PORT ATMEL AVR MCU SPI/JTAGATAVRISP2 - PROGRAMMER AVR IN SYSTEM
Lead Free Status / RoHS Status
Lead free / RoHS Compliant
Available stocks
Company
Part Number
Manufacturer
Quantity
Price
Company:
Part Number:
ATMEGA644P-20PU
Manufacturer:
Atmel
Quantity:
1 984
- Current page: 255 of 439
- Download datasheet (10Mb)
20.9
20.9.1
8011O–AVR–07/10
Register Description
ADMUX – ADC Multiplexer Selection Register
Example:
ADMUX = 0xED (ADC3 - ADC2, 10× gain, 2.56V reference, left adjusted result)
Voltage on ADC3 is 300 mV, voltage on ADC2 is 500 mV.
ADCR = 512 × 10 × (300 - 500) / 2560 = -400 = 0x270
ADCL will thus read 0x00, and ADCH will read 0x9C. Writing zero to ADLAR right adjusts the
result: ADCL = 0x70, ADCH = 0x02.
• Bit 7:6 – REFS1:0: Reference Selection Bits
These bits select the voltage reference for the ADC, as shown in
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 20-3.
Note:
• Bit 5 – ADLAR: ADC Left Adjust Result
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 conver-
sions. For a complete description of this bit, see
page
• Bits 4:0 – MUX4:0: Analog Channel and Gain 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
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
(0x7C)
Read/Write
Initial Value
REFS1
0
0
1
1
258.
If 10× og 200× gain is selected, only 2.56V should be used as Internal Voltage Reference.
REFS0
Voltage Reference Selections for ADC
REFS1
0
1
0
1
R/W
7
0
Voltage Reference Selection
AREF, Internal Vref turned off
AVCC with external capacitor at AREF pin
Internal 1.1V Voltage Reference with external capacitor at AREF pin
Internal 2.56V Voltage Reference with external capacitor at AREF pin
REFS0
R/W
6
0
ADLAR
R/W
5
0
MUX4
R/W
4
0
”ADCL and ADCH – The ADC Data Register” on
ATmega164P/324P/644P
MUX3
R/W
3
0
MUX2
R/W
2
0
Table 20-4 on page 256
Table
MUX1
R/W
1
0
20-3. If these bits are
MUX0
R/W
0
0
ADMUX
255
for
Related parts for ATMEGA644P-20PU
Image
Part Number
Description
Manufacturer
Datasheet
Request
R
Part Number:
Description:
Manufacturer:
Atmel Corporation
Datasheet:
Part Number:
Description:
IC AVR MCU FLASH 64K 44-QFN
Manufacturer:
Atmel
Datasheet:
Part Number:
Description:
IC AVR MCU FLASH 64K 44TQFP
Manufacturer:
Atmel
Datasheet:
Part Number:
Description:
IC AVR MCU FLASH 64K 40DIP
Manufacturer:
Atmel
Datasheet:
Part Number:
Description:
MCU AVR 64K FLASH 20MHZ 44TQFP
Manufacturer:
Atmel
Datasheet:
Part Number:
Description:
MCU AVR 64K FLASH 20MHZ 44QFN
Manufacturer:
Atmel
Datasheet:
Part Number:
Description:
Atmega644 8-bit Avr Microcontroller With 64k Bytes In-system Programmable Flash
Manufacturer:
ATMEL Corporation
Datasheet:
Part Number:
Description:
Manufacturer:
Atmel Corporation
Datasheet:
Part Number:
Description:
Manufacturer:
ATMEL Corporation
Datasheet:
Part Number:
Description:
Manufacturer:
ATMEL Corporation
Datasheet:
Part Number:
Description:
IC AVR MCU 64K 16MHZ 5V 64TQFP
Manufacturer:
Atmel
Datasheet:
Part Number:
Description:
IC AVR MCU 64K 16MHZ 5V 64-QFN
Manufacturer:
Atmel
Datasheet: