ATMEGA644P-A15MZ Atmel, ATMEGA644P-A15MZ Datasheet - Page 298

• Manufacturer Part Number: ATMEGA644P-A15MZ
• Description: MCU AVR 64KB FLASH 16MHZ 44QFN
• Manufacturer: Atmel
• Series: AVR® ATmegar

Specifications of ATMEGA644P-A15MZ

• Package / Case: 44-VQFN Exposed Pad
• Voltage - Supply (vcc/vdd): 2.7 V ~ 5.5 V
• Operating Temperature: -40°C ~ 125°C
• Speed: 16MHz
• Number Of I /o: 32
• Eeprom Size: 2K x 8
• Core Processor: AVR
• Program Memory Type: FLASH
• Ram Size: 4K x 8
• Program Memory Size: 64KB (64K x 8)
• Data Converters: A/D 8x10b
• Oscillator Type: Internal
• Peripherals: Brown-out Detect/Reset, POR, PWM, WDT
• Connectivity: I²C, SPI, UART/USART
• Core Size: 8-Bit
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

298
ATmega164P/324P/644P
Table 25-4.
Note:
Table 25-5.
Note:
The status of the Fuse bits is not affected by Chip Erase. Note that the Fuse bits are locked if
Lock bit1 (LB1) is programmed. Program the Fuse bits before programming the Lock bits.
Fuse High Byte
OCDEN
JTAGEN
SPIEN
WDTON
EESAVE
BOOTSZ1
BOOTSZ0
BOOTRST
Fuse Low Byte
CKDIV8
CKOUT
SUT1
SUT0
CKSEL3
CKSEL2
CKSEL1
CKSEL0
(1)
1. The SPIEN Fuse is not accessible in serial programming mode.
2. The default value of BOOTSZ1..0 results in maximum Boot Size. See
3. See
4. Never ship a product with the OCDEN Fuse programmed regardless of the setting of Lock bits
1. The default value of SUT1..0 results in maximum start-up time for the default clock source.
2. The default setting of CKSEL3..0 results in internal RC Oscillator @ 8 MHz. See
3. The CKOUT Fuse allow the system clock to be output on PORTB1. See
4. See
(3)
(4)
(4)
(3)
for details.
and JTAGEN Fuse. A programmed OCDEN Fuse enables some parts of the clock system to
be running in all sleep modes. This may increase the power consumption.
See
page 30
on page 38
Fuse High Byte
Fuse Low Byte
“WDTCSR – Watchdog Timer Control Register” on page 58
“System and Reset Characteristics” on page 332
“System Clock Prescaler” on page 38
for details.
Bit No
for details.
7
6
5
4
3
2
1
0
Bit No
7
6
5
4
3
2
1
0
Description
Enable OCD
Enable JTAG
Enable Serial Program and Data
Downloading
Watchdog Timer always on
EEPROM memory is preserved
through the Chip Erase
Select Boot Size (see
details)
Select Boot Size (see
details)
Select Reset Vector
Description
Divide clock by 8
Clock output
Select start-up time
Select start-up time
Select Clock source
Select Clock source
Select Clock source
Select Clock source
for details.
Table 25-9
Table 25-9
for details.
for
for
Default Value
1 (unprogrammed, OCD
disabled)
0 (programmed, JTAG enabled)
0 (programmed, SPI prog.
enabled)
1 (unprogrammed)
1 (unprogrammed, EEPROM
not preserved)
0 (programmed)
0 (programmed)
1 (unprogrammed)
Default Value
0 (programmed)
1 (unprogrammed)
1 (unprogrammed)
0 (programmed)
0 (programmed)
0 (programmed)
1 (unprogrammed)
0 (programmed)
for details.
Table 24-7 on page 291
“Clock Output Buffer”
(2)
(2)
(1)
(2)
(2)
(2)
7674F–AVR–09/09
Table 7-1 on
(1)
(2)