Finally I decided to build myown EEPROM design based on my knowledge.
I use three 74HC595 for addressing the chip (flash 29F040), and use bidirectional parallel port to connect data lines directly to EEPROM's data lines (with pull-down resistors).
Two control lines are to control clock and input for 74HC595s, and the other two control lines are used as Write enabled, Output enabled (for EEPROM)
really easy... I builded it in my protoboard, and made a control program under to test it. Actually it should be able to read and program it, but it does not work. Addresses not always are fine... I use pull-down resistors and some capcitors, ald decoupling IC capacitors.
Power supply by external DC adapter and 7805...
any help?
I use three 74HC595 for addressing the chip (flash 29F040), and use bidirectional parallel port to connect data lines directly to EEPROM's data lines (with pull-down resistors).
Two control lines are to control clock and input for 74HC595s, and the other two control lines are used as Write enabled, Output enabled (for EEPROM)
really easy... I builded it in my protoboard, and made a control program under to test it. Actually it should be able to read and program it, but it does not work. Addresses not always are fine... I use pull-down resistors and some capcitors, ald decoupling IC capacitors.
Power supply by external DC adapter and 7805...
any help?