ATMEGA644P-20PU Atmel, ATMEGA644P-20PU Datasheet - Page 294

• Manufacturer Part Number: ATMEGA644P-20PU
• Description: IC MCU AVR 64K FLASH 40-DIP
• Manufacturer: Atmel
• Series: AVR® ATmegar

Specifications of ATMEGA644P-20PU

• Core Processor: AVR
• Core Size: 8-Bit
• Speed: 20MHz
• Connectivity: I²C, SPI, UART/USART
• Peripherals: Brown-out Detect/Reset, POR, PWM, WDT
• Number Of I /o: 32
• Program Memory Size: 64KB (32K x 16)
• Program Memory Type: FLASH
• Eeprom Size: 2K x 8
• Ram Size: 4K x 8
• Voltage - Supply (vcc/vdd): 2.7 V ~ 5.5 V
• Data Converters: A/D 8x10b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 40-DIP (0.600", 15.24mm)
• Processor Series: ATMEGA64x
• Core: AVR8
• Data Bus Width: 8 bit
• Data Ram Size: 4 KB
• Interface Type: 2-Wire/JTAG/SPI/USART
• Maximum Clock Frequency: 20 MHz
• Number Of Programmable I/os: 32
• Number Of Timers: 3
• Maximum Operating Temperature: + 85 C
• Mounting Style: Through Hole
• 3rd Party Development Tools: EWAVR, EWAVR-BL
• Development Tools By Supplier: ATAVRDRAGON, ATSTK500, ATSTK600, ATAVRISP2, ATAVRONEKIT
• Minimum Operating Temperature: - 40 C
• On-chip Adc: 8-ch x 10-bit
• For Use With: ATSTK600-TQFP44 - STK600 SOCKET/ADAPTER 44-TQFPATSTK600 - DEV KIT FOR AVR/AVR32770-1007 - ISP 4PORT ATMEL AVR MCU SPI/JTAGATAVRISP2 - PROGRAMMER AVR IN SYSTEM
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

24.2
8011O–AVR–07/10
Fuse Bits
Table 24-2.
Notes:
The ATmega164P/324P/644P has four Fuse bytes.
functionality of all the fuses and how they are mapped into the Fuse bytes. Note that the fuses
are read as logical zero, “0”, if they are programmed.
Table 24-3.
Note:
–
–
–
–
–
BODLEVEL2
BODLEVEL1
BODLEVEL0
BLB1 Mode
Fuse Low Byte
1
2
3
4
1. Program the Fuse bits and Boot Lock bits before programming the LB1 and LB2.
2. “1” means unprogrammed, “0” means programmed
1. See
Memory Lock Bits
(1)
(1)
(1)
Lock Bit Protection Modes
Extended Fuse Byte
”System and Reset Characteristics” on page 331
BLB12
1
1
0
0
7
6
5
4
3
2
1
0
Bit No
BLB11
1
0
0
1
Description
–
–
–
–
–
Brown-out Detector trigger level
Brown-out Detector trigger level
Brown-out Detector trigger level
Protection Type
No restrictions for SPM or (E)LPM accessing the Boot Loader
section.
SPM is not allowed to write to the Boot Loader section.
SPM is not allowed to write to the Boot Loader section, and
(E)LPM executing from the Application section is not allowed to
read from the Boot Loader section. If Interrupt Vectors are
placed in the Application section, interrupts are disabled while
executing from the Boot Loader section.
(E)LPM executing from the Application section is not allowed to
read from the Boot Loader section. If Interrupt Vectors are
placed in the Application section, interrupts are disabled while
executing from the Boot Loader section.
(1)(2)
(Continued)
ATmega164P/324P/644P
Table 24-3
for BODLEVEL Fuse decoding.
-
Table 24-5
Default Value
1
1
1
1
1
1 (unprogrammed)
1 (unprogrammed)
1 (unprogrammed)
describe briefly the
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