ATmega1284 Atmel Corporation, ATmega1284 Datasheet - Page 23

• Manufacturer Part Number: ATmega1284
• Manufacturer: Atmel Corporation

Specifications of ATmega1284

• Flash (kbytes): 128 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): 16
• Eeprom (bytes): 4096
• Self Program Memory: YES
• Dram Memory: No
• Nand Interface: No
• Picopower: No
• 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

8.5
8272C–AVR–06/11
I/O Memory
The I/O space definition of the ATmega164A/164PA/324A/324PA/644A/644PA/1284/1284P is
shown in
All ATmega164A/164PA/324A/324PA/644A/644PA/1284/1284P I/Os and peripherals are placed
in the I/O space. All I/O locations may be accessed by the LD/LDS/LDD and ST/STS/STD
instructions, transferring data between the 32 general purpose working registers and the I/O
space. I/O Registers within the address range 0x00 - 0x1F are directly bit-accessible using the
SBI and CBI instructions. In these registers, the value of single bits can be checked by using the
SBIS and SBIC instructions. Refer to the instruction set section for more details. When using the
I/O specific commands IN and OUT, the I/O addresses 0x00 - 0x3F must be used. When
addressing I/O Registers as data space using LD and ST instructions, 0x20 must be added to
these addresses. The ATmega164A/164PA/324A/324PA/644A/644PA/1284/1284P is a com-
plex microcontroller with more peripheral units than can be supported within the 64 location
reserved in Opcode for the IN and OUT instructions. For the Extended I/O space from 0x60 -
0xFF in SRAM, only the ST/STS/STD and LD/LDS/LDD instructions can be used.
For compatibility with future devices, reserved bits should be written to zero if accessed.
Reserved I/O memory addresses should never be written.
Some of the Status Flags are cleared by writing a logical one to them. Note that, unlike most
other AVRs, the CBI and SBI instructions will only operate on the specified bit, and can therefore
be used on registers containing such Status Flags. The CBI and SBI instructions work with reg-
isters 0x00 to 0x1F only.
The I/O and peripherals control registers are explained in later sections.
The ATmega164A/164PA/324A/324PA/644A/644PA/1284/1284P contains three General Pur-
pose I/O Registers, see
storing any information, and they are particularly useful for storing global variables and Status
Flags. General Purpose I/O Registers within the address range 0x00 - 0x1F are directly bit-
accessible using the SBI, CBI, SBIS, and SBIC instructions.
”Register Summary” on page
ATmega164A/PA/324A/PA/644A/PA/1284/P
”Register Description” on page
553.
24. These registers can be used for
23