ATmega8A Atmel Corporation, ATmega8A Datasheet - Page 226

• Manufacturer Part Number: ATmega8A
• Manufacturer: Atmel Corporation

Specifications of ATmega8A

• 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
• Pwm Channels: 3
• 32khz Rtc: Yes
• Calibrated Rc Oscillator: Yes

24. Memory Programming
24.1
8159D–AVR–02/11
Program And Data Memory Lock Bits
The ATmega8A 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 24-1.
Note:
Table 24-2.
BLB12
BLB11
BLB02
BLB01
LB2
LB1
BLB0 Mode
LB Mode
Lock Bit Byte
1
2
3
1
2
3
4
1. “1” means unprogrammed, “0” means programmed
Memory Lock Bits
Lock Bit Byte
Lock Bit Protection Modes
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)
Table
24-2. The Lock Bits can only be
Default Value
1 (unprogrammed)
1 (unprogrammed)
1 (unprogrammed)
1 (unprogrammed)
1 (unprogrammed)
1 (unprogrammed)
1 (unprogrammed)
1 (unprogrammed)
ATmega8A
(1)
(1)
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