attiny167-esxz ATMEL Corporation, attiny167-esxz Datasheet - Page 21

• Manufacturer Part Number: attiny167-esxz
• Description: 8-bit Avr 8-bit Microcontroller Microcontroller With 16k Bytes In-system Programmable Flash And Lin Controller
• Manufacturer: ATMEL Corporation

3.5.2
3.5.3
7728A–AUTO–07/08
EEDR – EEPROM Data Register
EECR – EEPROM Control Register
addressed linearly between 0 and “E2 size”. The initial value of EEAR is undefined. A proper
value must be written before the EEPROM may be accessed.
Note:
• 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 7,6 – Res: Reserved Bits
These bits are reserved for future use and will always read as 0 in ATtiny167. After reading,
mask out these bits. For compatibility with future AVR devices, always write these bits to 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
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 3-2.
• Bit 3 – EERIE: EEPROM Ready Interrupt Enable
Writing EERIE to one enables the EEPROM Ready Interrupt if the I-bit in SREG is set. Writing
EERIE to zero disables the interrupt. The EEPROM Ready Interrupt generates a constant inter-
rupt when Non-volatile memory is ready for programming.
• Bit 2 – EEMPE: EEPROM Master Program Enable
The EEMPE bit determines whether writing EEPE to one will have effect or not.
Bit
Read/Write
Initial Value
Bit
Read/Write
Initial Value
EEPM1
0
0
1
1
For information only - ATtiny47: EEAR8 exists as register bit but it is not used for addressing.
EEPM0
EEPROM Mode Bits
EEDR7
0
1
0
1
R/W
R
7
0
7
–
0
Programming
EEDR6
R/W
R
6
0
6
–
0
Typical
3.4 ms
1.8 ms
1.8 ms
Time
–
EEDR5
EEPM1
R/W
R/W
5
0
5
X
Operation
Erase and Write in one operation (Atomic Operation)
Erase Only
Write Only
Reserved for future use
EEDR4
EEPM0
R/W
R/W
4
0
4
X
EEDR3
EERIE
R/W
R/W
3
0
3
0
EEMPE
EEDR2
R/W
R/W
2
0
2
0
EEDR1
EEPE
R/W
R/W
1
0
1
X
Table
ATtiny167
EEDR0
EERE
3-2. While EEPE
R/W
R/W
0
0
0
0
EEDR
EECR
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