Extract MCU is a complicate process since there are thousands of different kinds of new MCUs have been developed and launched each year, MCU extractr need to always keep up with the fast upgrading cycle of MCU and ensure they can figure out the new security way for decoding. In order to extract these keep on changing MCUs, we need to do a lots of experiments to test the availability of methods.

We hereby use a PIC16F84A from Microchip with FLASH & EEPROM, use the similar test sequence, and the difference is electrical erase. We can see the big difference of memorizer after extract MCU. Erase operation will start to execution and complete within 65-75 micro-seconds after the receipt of extract MCU memorizer operation order. But the time length can be variable accompany with the alteration of temperature and power supply voltage. For example, when heat up the MCU chip to 35 degrees, memorizer of MCU can start to wipe out the content without 60 micro-second after extract MCU and complete in 70 micro-second. Security fuse need at least 125 microsecond and at least 5 times reliable memorizer elimination operation for MCU extract. Decrease the power voltage will increase the memorizer and security fuse remove time length. So in a matter of fact, they are the same ratio.

There is thing need to pay attention is unless the application of hardware to reset the termination, the MCU wipe out operation need to last at least 1 microsecond. Plus the swiftly extract MCU time. Which give people the impression that there is no issue with the data security and maintainence from EEPROM & FLASH and can provide even better security protection.