ATmega168 Atmel Corporation, ATmega168 Datasheet - Page 233

• Manufacturer Part Number: ATmega168
• Manufacturer: Atmel Corporation

Specifications of ATmega168

• Flash (kbytes): 16 Kbytes
• Pin Count: 32
• Max. Operating Frequency: 20 MHz
• Cpu: 8-bit AVR
• # Of Touch Channels: 16
• Hardware Qtouch Acquisition: No
• Max I/o Pins: 23
• Ext Interrupts: 24
• Usb Speed: No
• Usb Interface: No
• Spi: 2
• Twi (i2c): 1
• Uart: 1
• Graphic Lcd: No
• Video Decoder: No
• Camera Interface: No
• Adc Channels: 8
• Adc Resolution (bits): 10
• Adc Speed (ksps): 15
• Analog Comparators: 1
• Resistive Touch Screen: No
• Temp. Sensor: No
• Crypto Engine: No
• Sram (kbytes): 1
• Eeprom (bytes): 512
• Self Program Memory: YES
• Dram Memory: No
• Nand Interface: No
• Picopower: No
• Temp. Range (deg C): -40 to 85
• I/o Supply Class: 1.8 to 5.5
• Operating Voltage (vcc): 1.8 to 5.5
• Fpu: No
• Mpu / Mmu: no / no
• Timers: 3
• Output Compare Channels: 6
• Input Capture Channels: 1
• Pwm Channels: 6
• 32khz Rtc: Yes
• Calibrated Rc Oscillator: Yes

Table 22-5.
2545T–AVR–05/11
Status code
(TWSR)
prescaler bits
are 0
0xA8
0xB0
0xB8
0xC0
0xC8
Status of the 2-wire serial bus
and 2-wire serial interface hard-
ware
Own SLA+R has been received;
ACK has been returned
Arbitration lost in SLA+R/W as
Master; own SLA+R has been
received; ACK has been returned
Data byte in TWDR has been
transmitted; ACK has been
received
Data byte in TWDR has been
transmitted; NOT ACK has been
received
transmitted (TWEA = “0”); ACK
has been received
Last data byte in TWDR has been
Status codes for slave transmitter mode.
To/from TWDR
Load data byte or
load data byte
Load data byte or
load data byte
Load data byte or
load data byte
No TWDR action or
no TWDR action or
no TWDR action or
no TWDR action
No TWDR action or
no TWDR action or
no TWDR action or
no TWDR action
Application software response
STA
X
X
X
X
X
X
0
0
1
1
0
0
1
1
STO
0
0
0
0
0
0
0
0
0
0
0
0
0
0
To TWCR
TWIN
T
1
1
1
1
1
1
1
1
1
1
1
1
1
1
TWE
A
0
1
0
1
0
1
0
1
0
1
0
1
0
1
Last data byte will be transmitted and NOT ACK should
be received
Data byte will be transmitted and ACK should be re-
ceived
Last data byte will be transmitted and NOT ACK should
be received
Data byte will be transmitted and ACK should be re-
ceived
Switched to the not addressed slave mode;
no recognition of own SLA or GCA
Switched to the not addressed slave mode;
own SLA will be recognized;
GCA will be recognized if TWGCE = “1”
Switched to the not addressed slave mode;
no recognition of own SLA or GCA;
a START condition will be transmitted when the bus
becomes free
Switched to the not addressed slave mode;
own SLA will be recognized;
GCA will be recognized if TWGCE = “1”;
a START condition will be transmitted when the bus
becomes free
Next action taken by TWI hardware
Last data byte will be transmitted and NOT ACK should
be received
Data byte will be transmitted and ACK should be re-
ceived
Switched to the not addressed slave mode;
no recognition of own SLA or GCA
Switched to the not addressed slave mode;
own SLA will be recognized;
GCA will be recognized if TWGCE = “1”
Switched to the not addressed slave mode;
no recognition of own SLA or GCA;
a START condition will be transmitted when the bus
becomes free
Switched to the not addressed slave mode;
own SLA will be recognized;
GCA will be recognized if TWGCE = “1”;
a START condition will be transmitted when the bus
becomes free
ATmega48/88/168
233