ATMEGA640V-8AU Atmel, ATMEGA640V-8AU Datasheet - Page 33

• Manufacturer Part Number: ATMEGA640V-8AU
• Description: IC MCU AVR 64K FLASH 100-TQFP
• Manufacturer: Atmel
• Series: AVR® ATmegar

Specifications of ATMEGA640V-8AU

• Core Processor: AVR
• Core Size: 8-Bit
• Speed: 8MHz
• Connectivity: EBI/EMI, I²C, SPI, UART/USART
• Peripherals: Brown-out Detect/Reset, POR, PWM, WDT
• Number Of I /o: 86
• Program Memory Size: 64KB (32K x 16)
• Program Memory Type: FLASH
• Eeprom Size: 4K x 8
• Ram Size: 8K x 8
• Voltage - Supply (vcc/vdd): 1.8 V ~ 5.5 V
• Data Converters: A/D 16x10b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 100-TQFP, 100-VQFP
• Processor Series: ATMEGA64x
• Core: AVR8
• Data Bus Width: 8 bit
• Data Ram Size: 8 KB
• Interface Type: 2-Wire, JTAG, SPI
• Maximum Clock Frequency: 16 MHz
• Number Of Programmable I/os: 86
• Number Of Timers: 8
• 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: 10 bit, 16 Channel
• Controller Family/series: AVR MEGA
• No. Of I/o's: 86
• Eeprom Memory Size: 4KB
• Ram Memory Size: 8KB
• Cpu Speed: 8MHz
• Rohs Compliant: Yes
• For Use With: ATSTK600-TQFP100 - STK600 SOCKET/ADAPTER 100-TQFP770-1007 - 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 SYSTEMATSTK503 - STARTER KIT AVR EXP MODULE 100P
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

2549MS–AVR–09/10
5. IN/OUT instructions may be executed twice when Stack is in external RAM
6. EEPROM read from application code does not work in Lock Bit Mode 3
- The actual value of the reference can be measured by applying a known voltage to the
ADC when using the internal reference. The result when doing later conversions can then be
calibrated.
If either an IN or an OUT instruction is executed directly before an interrupt occurs and the
stack pointer is located in external ram, the instruction will be executed twice. In some cases
this will cause a problem, for example:
- If reading SREG it will appear that the I-flag is cleared.
- If writing to the PIN registers, the port will toggle twice.
- If reading registers with interrupt flags, the flags will appear to be cleared.
Problem Fix/Workaround
There are two application workarounds, where selecting one of them, will be omitting the
issue:
- Replace IN and OUT with LD/LDS/LDD and ST/STS/STD instructions.
- Use internal RAM for stack pointer.
When the Memory Lock Bits LB2 and LB1 are programmed to mode 3, EEPROM read does
not work from the application code.
Problem Fix/Workaround
Do not set Lock Bit Protection Mode 3 when the application code needs to read from
EEPROM.
ATmega640/1280/1281/2560/2561
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