ATMEGA644V-10AU Atmel, ATMEGA644V-10AU Datasheet - Page 33

• Manufacturer Part Number: ATMEGA644V-10AU
• Description: IC AVR MCU FLASH 64K 44TQFP
• Manufacturer: Atmel
• Series: AVR® ATmegar

Specifications of ATMEGA644V-10AU

• Core Processor: AVR
• Core Size: 8-Bit
• Speed: 10MHz
• 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): 1.8 V ~ 5.5 V
• Data Converters: A/D 8x10b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 44-TQFP, 44-VQFP
• Processor Series: ATMEGA64x
• Core: AVR8
• Data Bus Width: 8 bit
• Data Ram Size: 4 KB
• Interface Type: 2-Wire/SPI/USART
• Maximum Clock Frequency: 10 MHz
• Number Of Programmable I/os: 32
• Number Of Timers: 3
• Operating Supply Voltage: 1.8 V to 5.5 V
• Maximum Operating Temperature: + 85 C
• Mounting Style: SMD/SMT
• Minimum Operating Temperature: - 40 C
• On-chip Adc: 8-ch x 10-bit
• Package: 44TQFP
• Device Core: AVR
• Family Name: ATmega
• Maximum Speed: 10 MHz
• For Use With: ATSTK600-TQFP44 - STK600 SOCKET/ADAPTER 44-TQFPATSTK600-DIP40 - STK600 SOCKET/ADAPTER 40-PDIP770-1007 - ISP 4PORT ATMEL AVR MCU SPI/JTAG770-1005 - ISP 4PORT FOR ATMEL AVR MCU JTAG770-1004 - ISP 4PORT FOR ATMEL AVR MCU SPIATAVRISP2 - PROGRAMMER AVR IN SYSTEM
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

7.6
2593N–AVR–07/10
Calibrated Internal RC Oscillator
By default, the Internal RC Oscillator provides an approximate 8 MHz clock. Though voltage and
temperature dependent, this clock can be very accurately calibrated by the user. See
on page 319
with the CKDIV8 Fuse programmed. See
This clock may be selected as the system clock by programming the CKSEL Fuses as shown in
Table
the pre-programmed calibration value into the OSCCAL Register and thereby automatically cal-
ibrates the RC Oscillator. The accuracy of this calibration is shown as Factory calibration in
Table 26-1 on page
By changing the OSCCAL register from SW, see
page
The accuracy of this calibration is shown as User calibration in
When this Oscillator is used as the chip clock, the Watchdog Oscillator will still be used for the
Watchdog Timer and for the Reset Time-out. For more information on the pre-programmed cali-
bration value, see the section
Table 7-8.
Notes:
When this Oscillator is selected, start-up times are determined by the SUT Fuses as shown in
Table 7-9 on page
Table 7-9.
Note:
Power Conditions
BOD enabled
Fast rising power
Slowly rising power
37, it is possible to get a higher calibration accuracy than by using the factory calibration.
7-8. If selected, it will operate with no external components. During reset, hardware loads
1. The device is shipped with this option selected.
2. The frequency ranges are preliminary values. Actual values are TBD.
3. If 8 MHz frequency exceeds the specification of the device (depends on V
1.
The device is shipped with this option selected.
Fuse can be programmed in order to divide the internal frequency by 8.
and
Internal Calibrated RC Oscillator Operating Modes
Start-up times for the internal calibrated RC Oscillator clock selection
Frequency Range
”Internal Oscillator Speed” on page 348
33.
319.
7.3 - 8.1
Start-up Time from Power-
”Calibration Byte” on page
down and Power-save
(2)
(MHz)
Reserved
6 CK
6 CK
6 CK
”System Clock Prescaler” on page 36
”OSCCAL – Oscillator Calibration Register” on
287.
for more details. The device is shipped
Additional Delay from
Reset (V
Table 26-1 on page
14CK + 65 ms
14CK + 4.1 ms
(1)(3)
14CK
CC
CKSEL3..0
ATmega644
= 5.0V)
0010
(1)
CC
for more details.
), the CKDIV8
319.
Table 26-1
SUT1..0
00
01
10
11
33