Crack ATmel ATmega16A Microcontroller Memory Program

Crack ATmel ATmega16A Microcontroller Memory Program

When the device has been powered or reset, disable then enable the Analog Comparator before the first conversion. Interrupts may be lost when writing the timer registers in the asynchronous timer, The interrupt will be lost in the process of Crack ATmel ATmega16A Microcontroller Memory Program if a timer register that is synchronized to the asynchronous timer clock is written when the asynchronous Timer/Counter register(TCNTx) is 0x00.

Problem Fix / Workaround
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).
IDCODE masks data from TDI input

The JTAG instruction IDCODE is not working correctly. Data to succeeding devices are replaced by all-ones during Update-DR.

Problem Fix / Workaround

If ATmega16 is the only device in the scan chain, the problem is not visible.
Select the Device ID Register of the ATmega16 by issuing the IDCODE instruction or by entering the Test-Logic-Reset state of the TAP controller to read out the contents of its Device ID Register and possibly data from succeeding devices of the scan chain. Issue the BYPASS instruction to the ATmega16 while reading the Device ID Registers of preceding devices of the boundary scan chain.

If the Device IDs of all devices in the boundary scan chain must be captured simultaneously, the ATmega16 must be the fist device in the chain.

Reading EEPROM by using ST or STS to set EERE bit triggers unexpected interrupt request.
Reading EEPROM by using the ST or STS command to set the EERE bit in the EECR register triggers an unexpected EEPROM interrupt request.

Problem Fix / Workaround
Always use OUT or SBI to set EERE in EECR.
First Analog Comparator conversion may be delayed

Interrupts may be lost when writing the timer registers in the asynchronous timer IDCODE masks data from TDI input

Reading EEPROM by using ST or STS to set EERE bit triggers unexpected interrupt request
First Analog Comparator conversion may be delayed. If the device is powered by a slow rising VCC, the first Analog Comparator conversion will take longer than expected on some devices from CRACK MCU.