ATMEGA649-16AUR Atmel, ATMEGA649-16AUR Datasheet - Page 25

• Manufacturer Part Number: ATMEGA649-16AUR
• Description: IC MCU AVR FLASH 64K 64TQFP
• Manufacturer: Atmel
• Series: AVR® ATmegar

Specifications of ATMEGA649-16AUR

• 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: 53
• 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): 2.7 V ~ 5.5 V
• Data Converters: A/D 8x10b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 64-TQFP
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

10.2
10.2.1
10.2.2
10.2.3
2552KS–AVR–04/11
ATmega3290
ATmega3290 rev. C
ATmega3290 rev. B
ATmega3290 rev. A
•
1. Interrupts may be lost when writing the timer registers in the asynchronous timer
Not sampled.
•
•
1. LCD contrast voltage too high
2. Interrupts may be lost when writing the timer registers in the asynchronous timer
Interrupts may be lost when writing the timer registers in the asynchronous timer
LCD contrast voltage too high
Interrupts may be lost when writing the timer registers in the asynchronous timer
The interrupt will be lost if a timer register that is synchronous timer clock is written when the
asynchronous Timer/Counter register (TCNTx) is 0x00.
Problem Fix/Wortkaround
Always check that the asynchronous Timer/Counter register neither have the value 0xFF nor
0x00 before writing to the asynchronous Timer Control Register (TCCRx), asynchronous
Timer Counter Register (TCNTx), or asynchronous Output Compare Register (OCRx).
When the LCD is active and using low power waveform, the LCD contrast voltage can be too
high. This occurs when V
Problem Fix/Workaround
There are several possible workarounds:
- Use normal waveform instead of low power waveform
- Use drivetime of 375 µs or longer
The interrupt will be lost if a timer register that is synchronous timer clock is written when the
asynchronous Timer/Counter register (TCNTx) is 0x00.
Problem Fix/Wortkaround
Always check that the asynchronous Timer/Counter register neither have the value 0xFF nor
0x00 before writing to the asynchronous Timer Control Register (TCCRx), asynchronous
Timer Counter Register (TCNTx), or asynchronous Output Compare Register (OCRx).
CC
is higher than V
ATmega329/3290/649/6490
LCD
, and when using low LCD drivetime.
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