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Altera_Forum's avatar
Altera_Forum
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10 years ago

Obtaining timing for parts with multiple IO voltages.

Dear forum,

In my role as a test engineer, I have been working on testing a epm9560ari240-10. From the m9000 data sheet, VCCIO can be set for either 5.0V or 3.3V operation.

I am doing some characterization testing at temperature for an industrial version of this chip, and have noticed that in measuring Tco at hot temperature, that the part does not

match the timing in the .tao file when testing at 3.3V. (Only off by a couple of hundred picoseconds, actually) My test passes just fine at 5.0V.

My engineering training tells me that yes, all timing should slow down somewhat when testing at a lower voltage. Therefore, my question is as follows:

Is there a way using the MAX+plus II (or Quartus) software to generate the timing.tao files for each of the particular VCCIO voltages? (In this case, a set of timing for 5V on the I/O's

vs. 3.3V on the I/O's...)

If you need additional information, please ask.

Software being used in this case:

-- MAX+plus II Version 10.1 06/12/2001

1 Reply

  • Altera_Forum's avatar
    Altera_Forum
    Icon for Honored Contributor rankHonored Contributor

    Quartus won't help you. MAX9000 devices are a little old.

    However, I think the answer is, yes. Providing MAX+Plus II allows you to specify the I/O voltage setting for VCCIO (my memory of it tells me you can), then it should generate an appropriate Timing Analyzer Output (tao) file.

    Curiosity and nostalgia may cause me to install the software again and check...

    Cheers,

    Alex