ATTIny2313-16MI ATMEL Corporation, ATTIny2313-16MI Datasheet - Page 17

• Manufacturer Part Number: ATTIny2313-16MI
• Description: 8-bit AVR Microcontroller with 2K Bytes In-System Programmable Flash
• Manufacturer: ATMEL Corporation

The EEPROM Address
Register
The EEPROM Data Register –
EEDR
The EEPROM Control Register
– EECR
2543C–AVR–12/03
• Bit 7 – Res: Reserved Bit
This bit is reserved in the ATtiny2313 and will always read as zero.
• Bits 6..0 – EEAR6..0: EEPROM Address
The EEPROM Address Register – EEAR specify the EEPROM address in the 128 bytes
EEPROM space. The EEPROM data bytes are addressed linearly between 0 and 127.
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 oper-
ation, the EEDR contains the data read out from the EEPROM at the address given by
EEAR.
• Bits 7..6 – Res: Reserved Bits
These bits are reserved bits in the ATtiny2313 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 opera-
tion (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 1. While 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.
Table 1. EEPROM Mode Bits
Bit
Read/Write
Initial Value
Bit
Read/Write
Initial Value
Bit
Read/Write
Initial Value
EEPM1
0
EEPM0
0
MSB
R/W
R
R
7
–
0
7
0
7
–
0
Programming
EEAR6
R/W
R/W
X
R
6
6
0
6
–
0
3.4 ms
Time
EEPM1
EEAR5
R/W
R/W
R/W
X
X
5
5
0
5
Operation
Erase and Write in one operation (Atomic Operation)
EEPM0
EEAR4
R/W
R/W
R/W
X
X
4
4
0
4
EEAR3
EERIE
R/W
R/W
R/W
X
3
3
0
3
0
EEAR2
EEMPE
R/W
R/W
R/W
X
2
2
0
2
0
ATtiny2313/V
EEAR1
EEPE
R/W
R/W
R/W
1
X
1
0
1
X
EEAR0
EERE
R/W
LSB
R/W
R/W
0
X
0
0
0
0
EEAR
EEDR
EECR
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