What will happen to RAM on Reset?

hi mohan

as per my knowledge contents of RAM is garbage only at hard reset.

for soft reset contents are same as before reset.

Thanks Nikhil,

I have tested this in the board. And you are right on this content.

But I am unable to get evidence from the TI datasheet.

I am in search of this evidence.

Thanks for replying.

Regards,

Mohan

Hi Matthew,

Thanks for your inputs,

In this link, they have special register to determine, the contents of the SRAM.

http://www.cypress.com/?id=4&rID=39458

Considering just RAM, the contents will be stored, until, the power is there.

But it depends on the design of the architecture. If the internal hardware is desinged

in such a way that, on receiving a reset signal, the power to the RAM to be removed.

Then, in that case, the contents of the RAM will be cleared on the reset.


Actually my requirement of this was to perform a Watchdog test, where I am supposed

to store the Watchdog test status and test enable data in RAM, as well need to

provide a solid evidence, stating that the data will not be lost, nor corrupt.

Matthew,  Is there any TI document, which I can refer as an evidence for the same, even though,

its a intrinsic property of RAM.

Hi Lori Heustess ,

Thanks for suggesting the answer.

Is there any document, which I can refer to insist the same.

Thanks,

Mohan

Mohan,

I don't know of an explicit document from TI only because SRAM is assumed to behave in the manner I posted.

The Cypress part is the exception here, in the fact the RAM gets initialized to 0 on Reset, which is why they have it documented.  This would have be implemented as special logic to do this outside the SRAM, which we do not have on our devices.  If we ever did something like this we would have to document in the same manner.

Best,

Matthew

Matthew,

Thanks for your reply..

I would consider this as intrinsic property of SRAM. And I will document the same in my notes.

Thanks Nikhil, Matthew, and Lori for your time and effort.

Regards,

Mohan