ATmega168A Atmel Corporation, ATmega168A Datasheet - Page 305

• Manufacturer Part Number: ATmega168A
• Manufacturer: Atmel Corporation

Specifications of ATmega168A

• 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: Yes
• 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
28.7.1
28.7.2
8271D–AVR–05/11
Parallel Programming
Enter Programming Mode
Considerations for Efficient Programming
Table 28-16. Command Byte Bit Coding
The following algorithm puts the device in Parallel (High-voltage) Programming mode:
1. Set Prog_enable pins listed in
2. Apply 4.5 - 5.5V between V
Ensure that V
3. Wait 20 - 60 µs, and apply 11.5 - 12.5V to RESET.
4. Keep the Prog_enable pins unchanged for at least 10µs after the High-voltage has been
5. Wait at least 300 µs before giving any parallel programming commands.
6. Exit Programming mode by power the device down or by bringing RESET pin to 0V.
If the rise time of the V
tive algorithm can be used.
1. Set Prog_enable pins listed in
2. Apply 4.5 - 5.5V between V
3. Monitor V
4. Keep the Prog_enable pins unchanged for at least 10µs after the High-voltage has been
5. Wait until V
6. Exit Programming mode by power the device down or by bringing RESET pin to 0V.
The loaded command and address are retained in the device during programming. For efficient
programming, the following should be considered.
• The command needs only be loaded once when writing or reading multiple memory locations.
• Skip writing the data value 0xFF, that is the contents of the entire EEPROM (unless the
• Address high byte needs only be loaded before programming or reading a new 256 word
EESAVE Fuse is programmed) and Flash after a Chip Erase.
window in Flash or 256 byte EEPROM. This consideration also applies to Signature bytes
reading.
Command Byte
V
applied to ensure the Prog_enable Signature has been latched.
V
applied to ensure the Prog_enable Signature has been latched.
commands.
CC
CC
0000 1000
0000 0100
0000 0010
0000 0011
to 0V.
to 0V.
CC
CC
CC
, and as soon as V
reaches at least 1.8V within the next 20 µs.
actually reaches 4.5 -5.5V before giving any parallel programming
ATmega48A/PA/88A/PA/168A/PA/328/P
Command Executed
Read Signature Bytes and Calibration byte
Read Fuse and Lock bits
Read Flash
Read EEPROM
CC
is unable to fulfill the requirements listed above, the following alterna-
CC
CC
Table 28-14 on page 304
and GND.
Table 28-14 on page 304
and GND.
CC
reaches 0.9 - 1.1V, apply 11.5 - 12.5V to RESET.
to “0000”, RESET pin to 0V and
to “0000”, RESET pin to 0V and
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