attiny167-esxz ATMEL Corporation, attiny167-esxz Datasheet - Page 22

• 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

3.5.4
3.5.5
3.5.6
22
ATtiny167
General Purpose I/O Register 2 – GPIOR2
General Purpose I/O Register 1 – GPIOR1
General Purpose I/O Register 0 – GPIOR0
When EEMPE is set, setting EEPE within four clock cycles will program the EEPROM at the
selected address. If EEMPE is zero, setting EEPE will have no effect. When EEMPE has been
written to one by software, hardware clears the bit to zero after four clock cycles.
• Bit 1 – EEPE: EEPROM Program Enable
The EEPROM Program Enable Signal EEPE is the programming enable signal to the EEPROM.
When EEPE is written, the EEPROM will be programmed according to the EEPMn bits setting.
The EEMPE bit must be written to one before a logical one is written to EEPE, otherwise no
EEPROM write takes place. When the write access time has elapsed, the EEPE bit is cleared by
hardware. When EEPE has been set, the CPU is halted for two cycles before the next instruction
is executed.
• Bit 0 – EERE: EEPROM Read Enable
The EEPROM Read Enable Signal – EERE – is the read strobe to the EEPROM. When the
correct address is set up in the EEAR Register, the EERE bit must be written to one to trigger
the EEPROM read. The EEPROM read access takes one instruction, and the requested data is
available immediately. When the EEPROM is read, the CPU is halted for four cycles before the
next instruction is executed. The user should poll the EEPE bit before starting the read opera-
tion. If a write operation is in progress, it is neither possible to read the EEPROM, nor to change
the EEAR Register.
Bit
Read/Write
Initial Value
Bit
Read/Write
Initial Value
Bit
Read/Write
Initial Value
GPIOR27
GPIOR17
GPIOR07
R/W
R/W
R/W
7
0
7
0
7
0
GPIOR26
GPIOR16
GPIOR06
R/W
R/W
R/W
6
0
6
0
6
0
GPIOR25
GPIOR15
GPIOR05
R/W
R/W
R/W
5
0
5
0
5
0
GPIOR24
GPIOR14
GPIOR04
R/W
R/W
R/W
4
0
4
0
4
0
GPIOR23
GPIOR13
GPIOR03
R/W
R/W
R/W
3
0
3
0
3
0
GPIOR22
GPIOR12
GPIOR02
R/W
R/W
R/W
2
0
2
0
2
0
GPIOR21
GPIOR11
GPIOR01
R/W
R/W
R/W
1
0
1
0
1
0
GPIOR20
GPIOR10
GPIOR00
R/W
R/W
R/W
0
0
0
0
0
0
7728A–AUTO–07/08
GPIOR2
GPIOR1
GPIOR0