Datasheet

12.7.3. EEDR – The EEPROM Data Register
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 offset
addresses. The device is a complex 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 in SRAM, only the ST/STS/STD and LD/LDS/LDD instructions can be used.
Name: EEDR
Offset: 0x1D
Reset: 0x00
Property: When addressing I/O Registers as data space the offset address is 0x3D
Bit 7 6 5 4 3 2 1 0
EEDR7 EEDR6 EEDR5 EEDR4 EEDR3 EEDR2 EEDR1 EEDR0
Access
R/W R/W R/W R/W R/W R/W R/W R/W
Reset 0 0 0 0 0 0 0 0
Bits 7:0 – EEDRn: EEPROM Data [n = 7:0]
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.
• EEDR[7] is MSB
• EEDR[0] is LSB
Atmel ATmega64A [DATASHEET]
Atmel-8160E-ATmega64A_Datasheet_Complete-09/2015
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