Chip extract technology has become prevail on the very old and low protection series of microcontrollers. In order to prevent the intellectual property being stolen by chip extractr. Semiconductor chip manufacturer will provide some effective measures for increasing the safety ability of chip against extract such as: the customized code on the surface of chip replace the standized chip part number.
Which will give the chip extractr the impression that the product was designed and made by customized integrated circuit. As we all know, ASIC provide a very good protection against multiple chip extract, only quite a little of chip extract cracker with sufficient experience and well equipped cracker can have the possibility to extract the chip successfully.
It is a very effective method which will force many chip extractr give up the trial. But a determined extractr will use some simple ways to identify if the chip is really a asic or not. The simplest way is monitor the pinouts of power supply, grounding, clock, reset, series and other interfaces.
Compare with the most suspected microcontroller in the datasheet and then chip extractr can understand if the so call ASIC one is real identity. It is a very reliable method since each one of chip will has its own pinout features. Once the similarities be found, it can be installed onto the programmer to try to read the firmware embedded.
Another simple way is limiting the program access sequence. This is a common method for smartcard, but it can also used on some chip. But it is not very practical and reliable method for chip deocde. The application of this method is well used in the smartcard. All the customers have been compelled to sign the non-proliferation protocol.
But microcontroller chip seldom has this situation, there are a lot of chip manufacturer in this world can provide the chips can be programmed by universal programmer. Even there is no configuration bits for them, with a low cost oscillograph can have the waveform required. If the chip extract can’t be supported by dedicated programmer, it can still obtain the complete protocol after the purchase of development board from manufacturer.