Hi,

 

Recently, I've started using NVRAM - Dallas DS1225AD - 150 in my design.


I designed a little "interface board", on which I put my NVRAM. It
connects it with ribbon cable to my PIC board ( also designed by me ).

I write something to RAM and then I read it several times. Every time I
read it I get some of the data different than it was when I read it the
previous time.

I thought that it could be something with timing so I extended reading
times. I made much longer than the minimum values in datasheet. It
didn't help.

I read in datasheet that the input have to be stable for certain time to
get data from it. The only possible cause coming to my head is that
outputs from my PIC board are not stable. 

Could it be the cause of it?

Is there any possibility of checking stability of outputs on PIC without
using oscilloscope?

What could cause unstable outputs on PIC? 

 

I'm using PIC18F8621 running at 40 MHz. Programming in Microchip C18.

 

I would be very grateful for help.

 

Thank you and best regards,

Sam 

 

  

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