To analyze the failure probability of microcontroller IC unlock and explore ways to reduce it, the process of FOCUS ION BEAM is necessary. However, it should be noted that this is a time-consuming and costly process, considering it is a critical step in microcontroller IC unlock.
A.The tape-out technology used in microcontroller ICs is becoming increasingly small, which makes it difficult to locate and unlock the security fuse. This is particularly evident in microcontroller ICs such as the PIC16C7X and PIC16C6X series.
B. When attempting to unlock microcontroller ICs, the strength of the electrical connection may not withstand the extended duration of the FOCUS ION BEAM, resulting in a failure of the process.
C. Insufficient control of the FOCUS ION BEAM during the microcontroller IC unlocking process may cause errors due to an excessive or insufficient amount of beam focus.
D. Malfunctioning of the imported FOCUS ION BEAM facilities, which are mostly acquired second-hand from dealers in Taiwan or the United States, may occasionally result in a failure rate, but not to the extent that it would significantly impact the microcontroller IC unlocking business.
E. Certain microcontroller IC unlocking procedures require multiple applications of FOCUS ION BEAM on the same area or at the same time, leading to a complex process that increases the likelihood of errors.
F. Some microcontroller IC designs intended to resist electrical static discharge, such as the AT89C2051, may not be adequately equipped to withstand damage during later procedures after FOCUS ION BEAM unlocking.
In addition to the reasons previously mentioned, there are other factors that may contribute to Microcontroller IC Unlock Failure Analysis. For instance, with the constant improvement of encryption technology, unlocking microcontroller ICs like the ATMEGA48 may result in alterations to the embedded firmware once read by the programmer.
Furthermore, we have encountered issues with software encryption on the tiny13v microcontroller IC. Our experiments showed that the extracted firmware could only be used on the original microcontroller IC after unlocking it. When we attempted to program it onto other attiny13v ICs, only one out of 256 new ones was workable.
Other causes of microcontroller IC unlock failure include programmer flaws, burned pinouts, broken protection circuits, and low-level misoperation. Some microcontroller IC unlocking processes are completed manually, such as with HT & MDT, which relies heavily on the operator’s experience and skill. Additionally, due to the program of microcontroller ICs being stored by the internal ion as media, some microcontroller ICs may fail to unlock due to the lengthy manufacturing date or external magnetic fields. Moreover, microcontroller ICs such as the GAL with time clocks and sequences may have a higher probability of failure when unlocked.
To recap the previously mentioned reasons, they include:
B. The extended duration of the FOCUS ION BEAM may cause the failure of the microcontroller IC unlocking process, as it can weaken the electrical connection.
C. Insufficient control of the FOCUS ION BEAM during the microcontroller IC unlocking process may lead to errors due to an excessive or insufficient amount of beam focus.
D. Malfunctioning imported FOCUS ION BEAM facilities, while present, do not significantly impact the overall business of microcontroller IC unlocking.
E. Certain microcontroller IC unlocking procedures require multiple applications of FOCUS ION BEAM on the same area or at the same time, which can increase the likelihood of errors.
F. The microcontroller IC design for anti-electrical static discharge, such as with the AT89C2051, may not be sufficient to prevent damage during the later stages of the unlocking process after FOCUS ION BEAM use.