Schematic serial memory copy

Electrically erasable memory is a readable and writable memory device, the English abbreviation for E2PROM, mainly used for saving data. 24CXX series which is more commonly used as a memory E2PROM. Widely used in all kinds of home appliances, such as TV IIC bus control, and the data storage machine working properly brightness, balanced face and other data. However, this memory can easily be damaged by static electricity loss of data stored to IIC bus control TV repair difficult. To make the data available in the market 24CXX series of memory, there is the original manufacturer of the machine working properly written, here's a copy of a serial memory device, which can be data storage appliances in the E2PROM write to a blank memory.

　　Analysis of the principle circuit diagram of the copy. Master chip microcontroller AT89C2051, the chip itself does not have the hardware IIC systems, so making the pure software simulation IIC bus, SDA access IC4 (19) feet. SCL access IC4 (18) feet.

　　IC4 (14) feet for the indicator LED driver (15) feet for the start button SB inputs.C3 and R4 form a power-on reset circuit. B and C4, C5 composition clock oscillation circuit. Plus the power to form a simple microcontroller applications. IC2, IC3 as two 8-pin DIP socket for inserting two 24CXX memory, which is the source IC2 memory, EEPROM from the TV. IC3 is the target storage, that commercially available blank E2PROM, the source memory address pins AO, A1, A2 take public places, except A2 target memory connected to VCC, the other also received public places. IC2, IC3's ④ feet grounded, ⑤ pin data cable SDA, ⑥ foot clock line SCL, ⑦ feet for the test side, under normal circumstances ground, ⑧ pin power supply Vcc (5V).

　　Access from the socket × 9 ~ 12V DC power supply, after three-terminal regulator fCl (78L05) regulator to provide 5V voltage of the entire circuit, the diode VD2 to prevent the external power supply circuit damage caused by reverse polarity. C1, C2 for filtering.

　　When used, the IC2, IC3 insert were the source and destination memory storage, power, LED low-speed flash to indicate normal operation, and then press the start button SB, then LED lit, said it is copied. Wait a period of time of about 20s .LED resumed flashing, indicating that the data has been copied to the target memory that the copy is complete, remove the power supply. At this point, two memory content data has been completely consistent, unplug the target insert memory can be used for maintenance spare, while the source of the memory can be inserted back into TV work.

　　Master chip microcontroller 89C2051 is commercially available, the software program must binary machine code by the programmer burned into the machine code can only be used for programming, if you want to read, you need to have the microcontroller compiler software to translate.

　　This copy is only applicable to 24C08 / C02 / 01 Series memory, while 24C16 read format with more memory due to the above-mentioned series of memory is different, it can not be applied.