ATMEGA8U2-MU Atmel, ATMEGA8U2-MU Datasheet - Page 246

• Manufacturer Part Number: ATMEGA8U2-MU
• Description: MCU AVR 8K FLASH USB 32-VQFN
• Manufacturer: Atmel
• Series: AVR® ATmegar

Specifications of ATMEGA8U2-MU

• Core Processor: AVR
• Core Size: 8-Bit
• Speed: 16MHz
• Connectivity: SPI, UART/USART, USB
• Peripherals: Brown-out Detect/Reset, POR, PWM, WDT
• Number Of I /o: 22
• Program Memory Size: 8KB (4K x 16)
• Program Memory Type: FLASH
• Eeprom Size: 512 x 8
• Ram Size: 512 x 8
• Voltage - Supply (vcc/vdd): 2.7 V ~ 5.5 V
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 32-VQFN Exposed Pad, 32-HVQFN, 32-SQFN, 32-DHVQFN
• Processor Series: ATMEGA8x
• Core: AVR8
• Data Bus Width: 8 bit
• Data Ram Size: 1 KB
• Interface Type: SPI, UART
• Maximum Clock Frequency: 16 MHz
• Number Of Programmable I/os: 22
• Number Of Timers: 2
• Maximum Operating Temperature: + 85 C
• Mounting Style: SMD/SMT
• 3rd Party Development Tools: EWAVR, EWAVR-BL
• Development Tools By Supplier: ATAVRDRAGON, ATSTK500, ATSTK600, ATAVRISP2, ATAVRONEKIT, AT90USBKEY, ATEVK525
• Minimum Operating Temperature: - 40 C
• Package: 32QFN EP
• Device Core: AVR
• Family Name: ATmega
• Maximum Speed: 16 MHz
• Operating Supply Voltage: 3.3|5 V
• For Use With: ATSTK600 - DEV KIT FOR AVR/AVR32ATSTK500 - PROGRAMMER AVR STARTER KIT
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Data Converters: -
• Lead Free Status / Rohs Status: Details

25. Memory Programming
25.1
7799D–AVR–11/10
Program And Data Memory Lock Bits
The ATmega8U2/16U2/32U2 provides six Lock bits which can be left unprogrammed (“1”) or
can be programmed (“0”) to obtain the additional features listed in
only be erased to “1” with the Chip Erase command.
Table 25-1.
Note:
Table 25-2.
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
(1)
LB1
1
0
0
1
0
0
1
Bit No
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 Boot Lock bits and Fuse bits are locked in both Serial and
Parallel Programming mode.
No restrictions for SPM or (E)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
(E)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.
(E)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.
(1)(2)
Description
–
–
Boot Lock bit
Boot Lock bit
Boot Lock bit
Boot Lock bit
Lock bit
Lock bit
ATmega8U2/16U2/32U2
(1)
Default Value
1 (unprogrammed)
1 (unprogrammed)
1 (unprogrammed)
0 (programmed)
1 (unprogrammed)
1 (unprogrammed)
0 (programmed)
0 (programmed)
Table
25-2. The Lock bits can
(1)
246