diode on output of eeprom

[franticEB]

Hello everyone I would like to connect my FPGA to a serial SPI EEPROM in this way


could the diode highlighted by the red arrow cause problems? may the logic levels of the signal not be correct? could the diode be suitable for that frequencies?

i want to put that diode because it is necessary that the FPGA reads a 1 (given by the pull-UP) on the specific input when eeprom is turned off.

Let me know thanks

 

[HTA]

Hello, the diode will not allow the MSIO of the EEPROM to generate a low level on "in". Why the EEPROM needs to be turned off?

Enjoy your design work!

 

[franticEB]

is there any way to solve my problem (read 1 when eeprom is turned off)?

could you explain me better what actually happens from electrical point of view please?

 

[HTA]

If you switch the EEPROM supply without bouncing from 3V to 0V the output should stay in a high impedance state. This way you just need the pull-up resitor but no diode.
Depending on the behavoir of the EEPROM with a open supply line a series resiter might be another option, but you need to know the EEPROM output high and low current/volatge levels.

Enjoy your design work!

 

[franticEB]

putting a diode in series with vcc of eeprom seems to solve my problem. What do you think about that?

 

[HTA]

If you tested this solution and if works, than it's fine for this case. It will not be a recommanded design for production.

Enjoy your design work!