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Non Volatile RAM (F-RAM & NVSRAM)

New Contributor

Hello,

regarding parallel FRAM devices, I wonder if there is a specified maximum CE# low time.

To be specific, in the FM18W08 device datasheet the following statement can be found (Pg4, Pre-Charge Operation):

"The user determines the beginning of this operation since a pre-charge will not begin until CE rises. However, the device has a maximum CE LOW time specification that must be satisfied."

So far I was not able to find a value or any other mentions of this parameter in the datasheet.

I did some tests and the device didn't seem to mind CE# low time intervals of couple hundred milliseconds or so, but I would like to be on the safe side. My usage scenario would involve an educational system in which components must operate in a static way, bus signals set by user through manual switches for example. This means that the bus could be in any one state for an indefinite amount of time, and obviously that is a concern for the FRAM if cited limit exists.

In the case this turns out to be a real issue with this and other parts in its product family, I would like to ask whether the FM28V020 device has the same restrictions, as it is said to be able to operate as a drop-in replacement for SRAM, which are by definition fully static.

Thanks.

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Moderator
Moderator

Hi,

There are no limit for CE# LOW time in our FRAM devices. Please make sure that CE# signal remain HIGH after every read/write operations for at least tPC (pre-charge time) time.

More details about pre-charge operation is available at: F-RAM Pre-Charge Operation - KBA203628

Thanks and Regards,

Sudheesh

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Moderator
Moderator

Hi,

There are no limit for CE# LOW time in our FRAM devices. Please make sure that CE# signal remain HIGH after every read/write operations for at least tPC (pre-charge time) time.

More details about pre-charge operation is available at: F-RAM Pre-Charge Operation - KBA203628

Thanks and Regards,

Sudheesh

View solution in original post

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New Contributor

Thank you very much, this is a nice feature.

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