With IC chip decode technology continues to evolve, new IC attack method is also emerging, changing the IC chip’s package, erase silkscreen on IC chip and burn out pins of IC chip as well as other methods being applied on electronic devices at home and abroad, erase silkscreen on IC chip is the most common method.
Of course, for such kind IC decryption, must first get to know the exact model number of the IC chip, a majority of companies use observation method like assessing the external circuit to estimate the probable models of IC chip, due to continuous development of IC chip, the limitations of this approach has been growing, mainly in the following several reasons:
1. Because IC from same company often has compatible pins (for example: MCU from PIC series and MCU of AVR series), so even determine which series IC chips in generally, but still difficult to determine its concrete model;
2. Today, different companies have compatible pins of IC chip is also very common (such as EMC78P156 and IC16C54C, etc.), which added more difficult for us to determine the final model number of IC chip;
3. Because different companies have different IC programming and verified pins distribution, especially the distribution of high-voltage VPP pin is different, so before the chip model has not been determined, random use of programmer to read the IC program (which is currently the most popular approach), it is very likely to cause damage of inside content in order to prove that you only need to take a AT90S2313 & AT89C2051 to do some experiments.