ATMEGA649A-AU Atmel, ATMEGA649A-AU Datasheet - Page 33

• Manufacturer Part Number: ATMEGA649A-AU
• Description: IC MCU AVR 64K FLASH 64TQFP
• Manufacturer: Atmel
• Series: AVR® ATmegar

Specifications of ATMEGA649A-AU

• Core Processor: AVR
• Core Size: 8-Bit
• Speed: 16MHz
• Connectivity: SPI, UART/USART, USI
• Peripherals: Brown-out Detect/Reset, LCD, POR, PWM, WDT
• Number Of I /o: 54
• 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: 64-TQFP
• Processor Series: ATmega
• Core: AVR
• Data Bus Width: 8 bit
• Data Ram Size: 4 KB
• Interface Type: SPI, USART
• Maximum Clock Frequency: 16 MHz
• Number Of Programmable I/os: 54
• Number Of Timers: 3
• Operating Supply Voltage: 3.3 V
• Maximum Operating Temperature: + 85 C
• Mounting Style: SMD/SMT
• Minimum Operating Temperature: - 40 C
• Operating Temperature Range: - 40 C to + 85 C
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

8284A–AVR–10/10
electromagnetic noise of the environment. Some initial guidelines for choosing capacitors for
use with crystals are given in
the manufacturer should be used.
Figure 8-2.
The Oscillator can operate in three different modes, each optimized for a specific frequency
range. The operating mode is selected by the fuses CKSEL3...1 as shown in
Table 8-5.
Note:
The CKSEL0 Fuse together with the SUT1...0 Fuses select the start-up times as shown in
8-6.
Table 8-6.
CKSEL0
ATmega169A/169PA/329A/329PA/649A/649P/3290A/3290PA/6490A/6490P
0
0
0
0
1
CKSEL3..1
1. This option should not be used with crystals, only with ceramic resonators.
100
101
110
111
(1)
SUT1..0
Crystal Oscillator Connections
Crystal Oscillator Operating Modes
Start-up Times for the Crystal Oscillator Clock Selection
00
01
10
11
00
Start-up Time from
Frequency Range
Power-down and
Power-save
Table
258 CK
258 CK
0.4 - 0.9
0.9 - 3.0
3.0 - 8.0
1K CK
1K CK
1K CK
(MHz)
8.0 -
8-5. For ceramic resonators, the capacitor values given by
C2
C1
(2)
(2)
(2)
(1)
(1)
Recommended Range for Capacitors C1 and
Additional Delay
14CK + 4.1 ms
14CK + 4.1 ms
14CK + 65 ms
14CK + 65 ms
(V
from Reset
CC
14CK
XTAL2
XTAL1
GND
C2 for Use with Crystals (pF)
= 5.0V)
12 - 22
12 - 22
12 - 22
–
Ceramic resonator, fast
rising power
Ceramic resonator,
slowly rising power
Recommended Usage
Ceramic resonator, fast
Ceramic resonator,
Ceramic resonator,
slowly rising power
Table
BOD enabled
rising power
8-5.
Table
33