ATmega8 Atmel Corporation, ATmega8 Datasheet - Page 204

• Manufacturer Part Number: ATmega8
• Manufacturer: Atmel Corporation

Specifications of ATmega8

• Flash (kbytes): 8 Kbytes
• Pin Count: 32
• Max. Operating Frequency: 16 MHz
• Cpu: 8-bit AVR
• # Of Touch Channels: 12
• Hardware Qtouch Acquisition: No
• Max I/o Pins: 23
• Ext Interrupts: 2
• Usb Speed: No
• Usb Interface: No
• Spi: 1
• 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: 2.7 to 5.5
• Operating Voltage (vcc): 2.7 to 5.5
• Fpu: No
• Mpu / Mmu: no / no
• Timers: 3
• Output Compare Channels: 3
• Input Capture Channels: 1
• Pwm Channels: 3
• 32khz Rtc: Yes
• Calibrated Rc Oscillator: Yes

Boot Loader Lock
Bits
204
ATmega8(L)
Figure 102. Memory Sections
Note:
If no Boot Loader capability is needed, the entire Flash is available for application code. The
Boot Loader has two separate sets of Boot Lock Bits which can be set independently. This gives
the user a unique flexibility to select different levels of protection.
The user can select:
•
•
•
•
See
be set in software and in Serial or Parallel Programming mode, but they can be cleared by a chip
erase command only. The general Write Lock (Lock bit mode 2) does not control the program-
ming of the Flash memory by SPM instruction. Similarly, the general Read/Write Lock (Lock bit
mode 3) does not control reading nor writing by LPM/SPM, if it is attempted.
To protect the entire Flash from a software update by the MCU
To protect only the Boot Loader Flash section from a software update by the MCU
To protect only the Application Flash section from a software update by the MCU
Allow software update in the entire Flash
Table 78 on page 205
1. The parameters in the figure are given in
Boot Loader Flash Section
Boot Loader Flash Section
Application Flash Section
Application Flash Section
Application Flash Section
Application Flash Section
Program Memory
Program Memory
BOOTSZ = '11'
BOOTSZ = '01'
and
(1)
Table 79 on page 205
$0000
End RWW
Start NRWW
End Application
Start Boot Loader
Flashend
$0000
End RWW
Start NRWW
End Application
Start Boot Loader
Flashend
Table 82 on page 213
Boot Loader Flash Section
Boot Loader Flash Section
Application Flash Section
Application Flash Section
for further details. The Boot Lock Bits can
Application flash Section
Program Memory
Program Memory
BOOTSZ = '10'
BOOTSZ = '00'
$0000
End RWW
Start NRWW
End Application
Start Boot Loader
Flashend
$0000
End RWW, End Application
Start NRWW, Start Boot Loader
Flashend
2486Z–AVR–02/11