Desprogramming xdata in uPSD3312 ( URGENT PLEASE)

[ricardof]

Posted on July 18, 2005 at 11:09

Desprogramming xdata in uPSD3312 ( URGENT PLEASE)

[ricardof]

Posted on May 17, 2011 at 12:07

I have a board with a uPSD3312, with 33,3volts and 5 vols supply. If I connect and desconnect quickly the supply sometimes the dates that I have recorded in xdata are desprogramming. Someone can dvice me if I have to introduce some electronic dispositic to avoid this problem. Thanks.

[jdaniel]

Posted on May 17, 2011 at 12:07

rifuvi,

I'm not sure I understand what you're saying. That's the way RAM works. If you remove the power, the contents turn to random junk when the power is reapplied. Depending on your definition of ''quickly,'' just adding some big capacitors to your power supply rails might hold the voltage up enough for temporary interruptions.

What you probably want to do is use some battery backup functionality to keep the contents of RAM held when you lose power.

[ricardof]

Posted on May 17, 2011 at 12:07

but my design has a battery of 3,3 volts. so in the case that I switch off and switch off quicly the dates of xdata shouldn´t change or not ?

[jdaniel]

Posted on May 17, 2011 at 12:07

Well... that is a bit strange then if you're holding up the voltage with a battery. Are you sure the hardware design is correct. Have you looked at the voltage on the chip with an oscilloscope to make sure it never dips below the required levels?

Another thing to consider is your reset code. Make sure that nothing is re-initializing your xdata after a reset. This would wipe out whatever you have there.