Electronic – Manual EEPROM Programming Problem

eeprommemoryprogramming

Image of circuit, the i/o pins also have jumper wires that I connect to VSS/Ground for inputting dataI have a 28c256-25 EEPROM that I have created a breadboard circuit to program. The datasheet says after the address is set and the data is put on the I/O pins, a low pulse on /WE while /OE and /CE are tied high should write that data into the provided address.

I have tried (using an RC circuit) giving a 33 nanosecond, 100 nanosecond, and 500 nanosecond negative pulse on /WE, but I could not get the data on the I/O pins to get written into memory. Here is the datasheet: https://www.jameco.com/Jameco/Products/ProdDS/74878XICOR.pdf
There is a short description of the Write cycle on page 4 and a timing diagram on page 14.Am I supposed to send the data on the I/O pins during or after the /WE pulse or something? What am I doing wrong?

Best Answer

As per your description, you keep /CE high and that keeps the whole chip disabled. /CE must be low to enable read or write operations.