ATmega644P Atmel Corporation, ATmega644P Datasheet - Page 72
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ATmega644P
Manufacturer Part Number
ATmega644P
Description
Manufacturer
Atmel Corporation
Specifications of ATmega644P
Flash (kbytes)
64 Kbytes
Pin Count
44
Max. Operating Frequency
20 MHz
Cpu
8-bit AVR
# Of Touch Channels
16
Hardware Qtouch Acquisition
No
Max I/o Pins
32
Ext Interrupts
32
Usb Speed
No
Usb Interface
No
Spi
3
Twi (i2c)
1
Uart
2
Graphic Lcd
No
Video Decoder
No
Camera Interface
No
Adc Channels
8
Adc Resolution (bits)
10
Adc Speed (ksps)
15
Analog Comparators
1
Resistive Touch Screen
No
Temp. Sensor
No
Crypto Engine
No
Sram (kbytes)
4
Eeprom (bytes)
2048
Self Program Memory
YES
Dram Memory
No
Nand Interface
No
Picopower
Yes
Temp. Range (deg C)
-40 to 85
I/o Supply Class
1.8 to 5.5
Operating Voltage (vcc)
1.8 to 5.5
Fpu
No
Mpu / Mmu
no / no
Timers
3
Output Compare Channels
6
Input Capture Channels
1
Pwm Channels
6
32khz Rtc
Yes
Calibrated Rc Oscillator
Yes
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Company
Part Number
Manufacturer
Quantity
Price
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Part Number:
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Quantity:
20 000
Company:
Part Number:
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Manufacturer:
Atmel
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1 984
Company:
Part Number:
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ATMEL
Quantity:
3 500
Part Number:
ATmega644P-A15MZ
Manufacturer:
ATMEL/爱特梅尔
Quantity:
20 000
Company:
Part Number:
ATmega644PA-AU
Manufacturer:
PHILIPS
Quantity:
450
Part Number:
ATmega644PA-AU
Manufacturer:
MICROCHIP/微芯
Quantity:
20 000
Company:
Part Number:
ATmega644PA-AUR
Manufacturer:
ATMEL
Quantity:
1 400
11. I/O-Ports
11.1
8011O–AVR–07/10
Overview
All AVR ports have true Read-Modify-Write functionality when used as general digital I/O ports.
This means that the direction of one port pin can be changed without unintentionally changing
the direction of any other pin with the SBI and CBI instructions. The same applies when chang-
ing drive value (if configured as output) or enabling/disabling of pull-up resistors (if configured as
input). Each output buffer has symmetrical drive characteristics with both high sink and source
capability. The pin driver is strong enough to drive LED displays directly. All port pins have indi-
vidually selectable pull-up resistors with a supply-voltage invariant resistance. All I/O pins have
protection diodes to both V
acteristics” on page 325
Figure 11-1. I/O Pin Equivalent Schematic
All registers and bit references in this section are written in general form. A lower case “x” repre-
sents the numbering letter for the port, and a lower case “n” represents the bit number. However,
when using the register or bit defines in a program, the precise form must be used. For example,
PORTB3 for bit no. 3 in Port B, here documented generally as PORTxn. The physical I/O Regis-
ters and bit locations are listed in
Three I/O memory address locations are allocated for each port, one each for the Data Register
– PORTx, Data Direction Register – DDRx, and the Port Input Pins – PINx. The Port Input Pins
I/O location is read only, while the Data Register and the Data Direction Register are read/write.
However, writing a logic one to a bit in the PINx Register, will result in a toggle in the correspond-
ing bit in the Data Register. In addition, the Pull-up Disable – PUD bit in MCUCR disables the
pull-up function for all pins in all ports when set.
Using the I/O port as General Digital I/O is described in
73. Most port pins are multiplexed with alternate functions for the peripheral features on the
device. How each alternate function interferes with the port pin is described in
Functions” on page
nate functions.
Pxn
78. Refer to the individual module sections for a full description of the alter-
for a complete list of parameters.
CC
and Ground as indicated in
”Register Description” on page
C
pin
ATmega164P/324P/644P
”Ports as General Digital I/O” on page
Figure
"General Digital I/O" for
91.
11-1. Refer to
See Figure
R
Details
pu
Logic
”Electrical Char-
”Alternate Port
72