ATmega8 Atmel Corporation, ATmega8 Datasheet - Page 215

• 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

Memory
Programming
Program And Data
Memory Lock Bits
2486Z–AVR–02/11
The ATmega8 provides six Lock Bits which can be left unprogrammed (“1”) or can be pro-
grammed (“0”) to obtain the additional features listed in
erased to “1” with the Chip Erase command.
Table 85. Lock Bit Byte
Note:
Table 86. Lock Bit Protection Modes
BLB12
BLB11
BLB02
BLB01
LB2
LB1
BLB0 Mode
LB Mode
Lock Bit Byte
1
2
3
1
2
3
4
Memory Lock Bits
1. “1” means unprogrammed, “0” means programmed
BLB02
LB2
1
1
0
1
1
0
0
BLB01
LB1
Bit No.
1
0
0
1
0
0
1
7
6
5
4
3
2
1
0
Protection Type
No memory lock features enabled
Further programming of the Flash and EEPROM is
disabled in Parallel and Serial Programming mode. The
Fuse Bits are locked in both Serial and Parallel
Programming mode
Further programming and verification of the Flash and
EEPROM is disabled in parallel and Serial Programming
mode. The Fuse Bits are locked in both Serial and Parallel
Programming modes
No restrictions for SPM or LPM accessing the Application
section
SPM is not allowed to write to the Application section
SPM is not allowed to write to the Application section, and
LPM executing from the Boot Loader section is not
allowed to read from the Application section. If Interrupt
Vectors are placed in the Boot Loader section, interrupts
are disabled while executing from the Application section
LPM executing from the Boot Loader section is not
allowed to read from the Application section. If Interrupt
Vectors are placed in the Boot Loader section, interrupts
are disabled while executing from the Application section
(2)
Description
–
–
Boot lock bit
Boot lock bit
Boot lock bit
Boot lock bit
Lock bit
Lock bit
(1)
(1)
Table
Default Value
1 (unprogrammed)
1 (unprogrammed)
1 (unprogrammed)
1 (unprogrammed)
1 (unprogrammed)
1 (unprogrammed)
1 (unprogrammed)
1 (unprogrammed)
86. The Lock Bits can only be
(1)
ATmega8(L)
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