ATtiny84 Atmel Corporation, ATtiny84 Datasheet - Page 21

• Manufacturer Part Number: ATtiny84
• Manufacturer: Atmel Corporation

Specifications of ATtiny84

• Flash (kbytes): 8 Kbytes
• Pin Count: 14
• Max. Operating Frequency: 20 MHz
• Cpu: 8-bit AVR
• # Of Touch Channels: 6
• Hardware Qtouch Acquisition: No
• Max I/o Pins: 12
• Ext Interrupts: 12
• Usb Speed: No
• Usb Interface: No
• Spi: 1
• Twi (i2c): 1
• 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: Yes
• Crypto Engine: No
• Sram (kbytes): 0.5
• Eeprom (bytes): 512
• 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: 2
• Output Compare Channels: 4
• Input Capture Channels: 1
• Pwm Channels: 4
• 32khz Rtc: No
• Calibrated Rc Oscillator: Yes

5.5.2
5.5.3
5.5.4
8006K–AVR–10/10
EEARL – EEPROM Address Register
EEDR – EEPROM Data Register
EECR – EEPROM Control Register
• Bit 7 – EEAR7: EEPROM Address
This is the most significant EEPROM address bit of ATtiny44. In devices with less EEPROM, i.e.
ATtiny24, this bit is reserved and will always read zero. The initial value of the EEPROM
Address Register (EEAR) is undefined and a proper value must therefore be written before the
EEPROM is accessed.
• Bits 6:0 – EEAR6:0: EEPROM Address
These are the (low) bits of the EEPROM Address Register. The EEPROM data bytes are
addressed linearly in the range 0...128/256/512. The initial value of EEAR is undefined and a
proper value must be therefore be written before the EEPROM may be accessed.
• Bits 7:0 – EEDR7:0: EEPROM Data
For the EEPROM write operation the EEDR Register contains the data to be written to the
EEPROM in the address given by the EEAR Register. For the EEPROM read operation, the
EEDR contains the data read out from the EEPROM at the address given by EEAR.
• Bit 7 – Res: Reserved Bit
This bit is reserved for future use and will always read as 0 in ATtiny24/44/84. For compatibility
with future AVR devices, always write this bit to zero. After reading, mask out this bit.
• Bit 6 – Res: Reserved Bit
This bit is reserved in the ATtiny24/44/84 and will always read as zero.
• Bits 5:4 – EEPM1, EEPM0: EEPROM Programming Mode Bits
The EEPROM Programming mode bits setting defines which programming action that will be
triggered when writing EEPE. It is possible to program data in one atomic operation (erase the
Bit
0x1E (0x3E)
Read/Write
Initial Value
Bit
0x1D (0x3D)
Read/Write
Initial Value
Bit
0x1C (0x3C)
Read/Write
Initial Value
EEAR7
EEDR7
R/W
R/W
R
X
7
7
0
7
–
0
EEAR6
EEDR6
R/W
R/W
R
X
6
6
0
6
–
0
EEAR5
EEDR5
EEPM1
R/W
R/W
R/W
X
X
5
5
0
5
EEAR4
EEDR4
EEPM0
R/W
R/W
R/W
X
X
4
4
0
4
EEAR3
EEDR3
EERIE
R/W
R/W
R/W
X
3
3
0
3
0
EEMPE
EEAR2
EEDR2
R/W
R/W
R/W
X
2
2
0
2
0
ATtiny24/44/84
EEAR1
EEDR1
EEPE
R/W
R/W
R/W
X
X
1
1
0
1
EEAR0
EEDR0
EERE
R/W
R/W
R/W
X
0
0
0
0
0
EEARL
EEDR
EECR
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