ATMEGA16U4-MU Atmel, ATMEGA16U4-MU Datasheet - Page 333

• Manufacturer Part Number: ATMEGA16U4-MU
• Description: MCU AVR 16K FLASH 16MHZ 44-QFN
• Manufacturer: Atmel
• Series: AVR® ATmegar

Specifications of ATMEGA16U4-MU

• Core Processor: AVR
• Core Size: 8-Bit
• Speed: 16MHz
• Connectivity: I²C, SPI, UART/USART, USB
• Peripherals: Brown-out Detect/Reset, POR, PWM, Temp Sensor, WDT
• Number Of I /o: 26
• Program Memory Size: 16KB (8K x 16)
• Program Memory Type: FLASH
• Eeprom Size: 512 x 8
• Ram Size: 1.25K x 8
• Voltage - Supply (vcc/vdd): 2.7 V ~ 5.5 V
• Data Converters: A/D 12x10b
• Oscillator Type: External
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 44-VQFN
• For Use With: ATSTK600 - DEV KIT FOR AVR/AVR32ATAVRDRAGON - KIT DRAGON 32KB FLASH MEM AVRATSTK500 - PROGRAMMER AVR STARTER KIT
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Other names: ATMEGA16U4-16MU; ATMEGA16U4-16MU

27.4
7766F–AVR–11/10
Boot Loader Lock Bits
Figure 27-2. 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
in Serial or in Parallel Programming mode. They can only be cleared by a Chip Erase command
only. The general Write Lock (Lock Bit mode 2) does not control the programming of the Flash
memory by SPM instruction. Similarly, the general Read/Write Lock (Lock Bit mode 1) does not
control reading nor writing by (E)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 27-2
1. The parameters in the figure above 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
and
BOOTSZ = '11'
BOOTSZ = '01'
Table 27-3
for further details. The Boot Lock bits can be set by software and
0x0000
End RWW
Start NRWW
End Application
Start Boot Loader
Flashend
0x0000
End RWW
Start NRWW
End Application
Start Boot Loader
Flashend
Boot Loader Flash Section
Boot Loader Flash Section
Application Flash Section
Application Flash Section
Application Flash Section
Table 27-8 on page
Program Memory
Program Memory
BOOTSZ = '10'
BOOTSZ = '00'
ATmega16/32U4
344.
0x0000
End RWW
Start NRWW
End Application
Start Boot Loader
Flashend
0x0000
End RWW, End Application
Start NRWW, Start Boot Loader
Flashend
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