ata5773 ATMEL Corporation, ata5773 Datasheet - Page 73

• Manufacturer Part Number: ata5773
• Description: Microcontroller With Uhf Ask/fsk Transmitter
• Manufacturer: ATMEL Corporation

5.5.3
5.5.4
8006G–AVR–01/08
EEDR – EEPROM Data Register
EECR – EEPROM Control Register
• Bits 7..0 – EEAR7..0: EEPROM Address
The EEPROM Address Register – EEARL – specifies the EEPROM address. In the 128 bytes
EEPROM space in ATiny24 bit 7 is reserved and always read as zero. The EEPROM data bytes
are addressed linearly between 0 and 128/256/512. The initial value of EEAR is undefined. A
proper value must 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 and 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
old value and program the new value) or to split the Erase and Write operations in two different
operations. The Programming times for the different modes are shown in
Table 5-1.
When EEPE is set any write to EEPMn will be ignored. During reset, the EEPMn bits will be
reset to 0b00 unless the EEPROM is busy programming.
Bit
0x1D (0x3D)
Read/Write
Initial Value
Bit
0x1C (0x3C)
Read/Write
Initial Value
EEPM1
0
0
1
1
EEPM0
EEPROM Programming Mode Bits and Programming Times
EEDR7
0
1
0
1
R/W
R
7
0
7
–
0
Programming Time
EEDR6
R/W
R
6
0
6
–
0
3.4 ms
1.8 ms
1.8 ms
–
EEDR5
EEPM1
R/W
R/W
X
5
0
5
EEDR4
EEPM0
R/W
R/W
X
4
0
4
Operation
Erase and Write in one operation (Atomic Operation)
Erase Only
Write Only
Reserved for future use
EEDR3
EERIE
R/W
R/W
3
0
3
0
EEMPE
EEDR2
R/W
R/W
2
0
2
0
ATtiny24/44/84
EEDR1
EEPE
R/W
R/W
X
1
0
1
Table
EEDR0
EERE
R/W
R/W
5-1.
0
0
0
0
EEDR
EECR
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