Hello.
I try to write to a EEPROM GLS29EE010 (Attachment). Because I'm not an english native speaker, I may understand something wrong. I try to use the WE controlled write cycle, and it seems like the address get latched at falling edge, the data get latched at the rising edge and the time between rising and falling edge must be below than 100µs, else the page write cycle starts.
I used a Monostable 555 Timer to handle this. If I did no mistake, the duration should be a bit more than 10µs. I have tested it with a bigger capacitor. Except the Timer to the WE of the ROM are all other pins wired by jump wires.

At the start is WE pushed to high while CE is direct wired to low.
I set up the first address ($5555) and activate the switch SW1.
Now is WE low and the address latched.
I set up the first data ($AA), the second address ($2AAA) and press the button.
Now goes the WE high, the data are latched, and fast back to low, which latch the second address.
I set up the second data, the third address, press the button; and so on...

But after sending the three-byte write init data and write to address 0, nothing changed. I have no idea what goes wrong.

Thank you very much.

 

The switches will have contact bounce and this will result in multiple pulses on WE so the initial address and data will be latched multiple times and the SDP will fail.

What are you trying to achieve?

 

Thank you. I want to write microcode (instruction decoding) into ROMs. I thought the capacitor between the momentary button and the trigger catch bounces.

 

I thought the capacitor between the momentary button and the trigger catch bounces.

No it won't as the period of the '555 is much shorter than the switch bounce period.
Note that both switches will produce multiple pulses.