ATMEGA644V-10AU Atmel, ATMEGA644V-10AU Datasheet - Page 145

• 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

15.10 Timer/Counter Prescaler
2593N–AVR–07/10
Figure 15-12. Prescaler for Timer/Counter2
The clock source for Timer/Counter2 is named clk
system I/O clock clk
clocked from the TOSC1 pin. This enables use of Timer/Counter2 as a Real Time Counter
(RTC). When AS2 is set, pins TOSC1 and TOSC2 are disconnected from Port C. A crystal can
then be connected between the TOSC1 and TOSC2 pins to serve as an independent clock
source for Timer/Counter2. The Oscillator is optimized for use with a 32.768 kHz crystal. By set-
ting the EXCLK bit in the ASSR, a 32 kHz external clock can be applied. See
Asynchronous Status Register” on page 150
For Timer/Counter2, the possible prescaled selections are: clk
clk
Setting the PSRASY bit in GTCCR resets the prescaler. This allows the user to operate with a
predictable prescaler.
T2S
/128, clk
PSRASY
TOSC1
clk
CS20
CS21
CS22
AS2
I/O
T2S
/256, and clk
IO
. By setting the AS2 bit in ASSR, Timer/Counter2 is asynchronously
clk
T2S
T2S
/1024. Additionally, clk
Clear
for details.
TIMER/COUNTER2 CLOCK SOURCE
T2S
0
. clk
10-BIT T/C PRESCALER
T2S
T2S
clk
as well as 0 (stop) may be selected.
T2
is by default connected to the main
T2S
/8, clk
ATmega644
T2S
/32, clk
”ASSR –
T2S
/64,
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