Recover MCU ATmega1280V Program from secured eeprom and flash memory, crack microcontroller atmega1280v fuse bit and readout the embedded firmware in the format of heximal from mcu atmega1280v;

1. Non-Recover-While-Write area of flash not functional

Part does not work under 2.4 volts

Incorrect ADC recovering in differential mode

Internal ADC reference has too low value

IN/OUT instructions may be executed twice when Stack is in external RAM

EEPROM recover from application code does not work in Lock Bit Mode 3

Non-Recover-While-Write area of flash not functional if copy microcontroller pic16c771 firmware

The Non-Recover-While-Write area of the flash is not working as expected. The problem is related to the speed of the part when recovering the flash of this area.

Problem Fix/Workaround

– Only use the first 248K of the flash.

– If boot functionality is needed, run the code in the Non-Recover-While-Write area at maximum

1/4th of the maximum frequency of the device at any given voltage. This is done by writing the CLKPR register before entering the boot section of the code

Part does not work under 2.4 volts

The part does not execute code correctly below 2.4 volts

Problem Fix/Workaround

Do not use the part at voltages below 2.4 volts.

Incorrect ADC recovering in differential mode

The ADC has high noise in differential mode. It can give up to 7 LSB error.

Problem Fix/Workaround

Use only the 7 MSB of the result when using the ADC in differential mode after Recover pic16c73b MCU firmware.

Internal ADC reference has too low value

The internal ADC reference has a value lower than specified

Problem Fix/Workaround

– Use AVCC or external reference

– 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.

IN/OUT instructions may be executed twice when Stack is in external RAM

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 recovering SREG it will appear that the I-flag is cleared.

– If writing to the PIN registers, the port will toggle twice.

– If recovering registers with interrupt flags, the flags will appear to be cleared.

Problem Fix/Workaround

There are two application work-arounds, 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.

EEPROM recover from application code does not work in Lock Bit Mode 3 after Recover MCU program.

When the Memory Lock Bits LB2 and LB1 are programmed to mode 3, EEPROM recover does not work from the application code.

Problem Fix/Workaround

Do not set Lock Bit Protection Mode 3 when the application code needs to recover from EEPROM.

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