ATMEGA649A-AU Atmel, ATMEGA649A-AU Datasheet - Page 241

• 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

23.3.3
23.3.4
8284A–AVR–10/10
1/3 Duty and 1/3 Bias
1/4 Duty and 1/3 Bias
Figure 23-4. Driving a LCD with Two Common Terminals
1/3 bias is usually recommended for LCD with three common terminals (1/3 duty). Waveform is
shown in
COM1 is the voltage across a segment that is off.
Figure 23-5. Driving a LCD with Three Common Terminals
1/3 bias is optimal for LCD displays with four common terminals (1/4 duty). Waveform is shown
in
- COM1 is the voltage across a segment that is off.
Figure 23-6 on page
ATmega169A/169PA/329A/329PA/649A/649P/3290A/3290PA/6490A/6490P
-
-
2
1
2
1
2
1
1
2
-1
1
1
/
/
/
/
/
/
/
/
3
3
3
3
3
3
3
3
-V
/
/
/
V
V
V
GND
V
V
V
GND
V
V
V
GND
V
V
2
2
2
-V
V
V
V
V
V
V
GND
GND
GND
LCD
LCD
LCD
LCD
LCD
LCD
LCD
LCD
LCD
LCD
LCD
LCD
Figure
LCD
LCD
LCD
LCD
LCD
LCD
LCD
Frame
Frame
23-5. SEG0 - COM0 is the voltage across a segment that is on and SEG0-
242. SEG0 - COM0 is the voltage across a segment that is on and SEG0
Frame
Frame
SEG0
COM0
SEG0 - COM0
SEG0
COM0
SEG0 - COM0
-
-
-1
2
1
2
1
2
1
1
2
1
1
/
/
/
/
/
/
/
/
3
3
3
3
3
3
3
3
/
/
/
-V
2
2
2
V
V
V
V
V
V
V
V
V
V
V
GND
GND
GND
-V
V
GND
V
V
GND
V
V
GND
V
LCD
LCD
LCD
LCD
LCD
LCD
LCD
LCD
LCD
LCD
LCD
LCD
LCD
LCD
LCD
LCD
LCD
LCD
LCD
Frame
Frame
Frame
Frame
SEG0
COM1
SEG0 - COM1
SEG0
COM1
SEG0 - COM1
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