ATTINY24-20SSUR Atmel, ATTINY24-20SSUR Datasheet - Page 21

• Manufacturer Part Number: ATTINY24-20SSUR
• Description: MCU AVR 2KB FLASH 20MHZ 14SOIC
• Manufacturer: Atmel
• Series: AVR® ATtinyr

Specifications of ATTINY24-20SSUR

• Core Processor: AVR
• Core Size: 8-Bit
• Speed: 20MHz
• Connectivity: USI
• Peripherals: Brown-out Detect/Reset, POR, PWM, Temp Sensor, WDT
• Number Of I /o: 12
• Program Memory Size: 2KB (1K x 16)
• Program Memory Type: FLASH
• Eeprom Size: 128 x 8
• Ram Size: 128 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: *
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

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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