ATmega168 Atmel Corporation, ATmega168 Datasheet - Page 298

• 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

28.7.14
28.7.15
28.8
2545T–AVR–05/11
Serial downloading
Reading the calibration byte
Parallel programming characteristics
The algorithm for reading the Calibration byte is as follows (refer to
page 292
1. A: Load Command “0000 1000”.
2. B: Load Address Low Byte, 0x00.
3. Set OE to “0”, and BS1 to “1”. The Calibration byte can now be read at DATA.
4. Set OE to “1”.
For characteristics of the parallel programming, see
page
Both the Flash and EEPROM memory arrays can be programmed using the serial SPI bus while
RESET is pulled to GND. The serial interface consists of pins SCK, MOSI (input) and MISO (out-
put). After RESET is set low, the Programming Enable instruction needs to be executed first
before program/erase operations can be executed. NOTE, in
mapping for SPI programming is listed. Not all parts use the SPI pins dedicated for the internal
SPI interface.
Figure 28-7. Serial programming and verify
Notes:
When programming the EEPROM, an auto-erase cycle is built into the self-timed programming
operation (in the Serial mode ONLY) and there is no need to first execute the Chip Erase
instruction. The Chip Erase operation turns the content of every memory location in both the
Program and EEPROM arrays into 0xFF.
Depending on CKSEL Fuses, a valid clock must be present. The minimum low and high periods
for the serial clock (SCK) input are defined as follows:
Low: > 2 CPU clock cycles for f
High: > 2 CPU clock cycles for f
312.
1. If the device is clocked by the internal Oscillator, it is no need to connect a clock source to the
2. V
for details on Command and Address loading):
XTAL1 pin.
CC
- 0.3V < AV
CC
< V
MOSI
MISO
SCK
CC
ck
ck
+ 0.3V, however, AV
< 12MHz, 3 CPU clock cycles for f
< 12MHz, 3 CPU clock cycles for f
XTAL1
RESET
GND
(1)
.
CC
AVCC
“Parallel programming characteristics” on
VCC
should always be within 1.8V - 5.5V
+1.8V - 5.5V
+1.8V - 5.5V
ATmega48/88/168
Table 28-15 on page
(2)
“Programming the flash” on
ck
ck
>= 12MHz
>= 12MHz
299, the pin
298