ATMEGA2561-16AI Atmel, ATMEGA2561-16AI Datasheet - Page 33
![IC AVR MCU 256K 16MHZ 64TQFP](/photos/12/13/121332/313-64-tqfp_sml.jpg)
ATMEGA2561-16AI
Manufacturer Part Number
ATMEGA2561-16AI
Description
IC AVR MCU 256K 16MHZ 64TQFP
Manufacturer
Atmel
Series
AVR® ATmegar
Specifications of ATMEGA2561-16AI
Core Processor
AVR
Core Size
8-Bit
Speed
16MHz
Connectivity
EBI/EMI, I²C, SPI, UART/USART
Peripherals
Brown-out Detect/Reset, POR, PWM, WDT
Number Of I /o
54
Program Memory Size
256KB (128K x 16)
Program Memory Type
FLASH
Eeprom Size
4K x 8
Ram Size
8K x 8
Voltage - Supply (vcc/vdd)
4.5 V ~ 5.5 V
Data Converters
A/D 8x10b
Oscillator Type
Internal
Operating Temperature
-40°C ~ 85°C
Package / Case
64-TQFP, 64-VQFP
Lead Free Status / RoHS Status
Contains lead / RoHS non-compliant
Available stocks
Company
Part Number
Manufacturer
Quantity
Price
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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