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Altera_Forum
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14 years ago

Why MAXII CPLD only output 1.6v when high (3.3V LVTTL)

VCCIO and VCCINT are both 3.3v, and the pins are set to 3.3v LVTTL in quartusII, but the output is only 1.6v when high after I downloaded my program into the device(epm240t100c5) Could any bod...
Altera_Forum's avatar
Altera_Forum
Icon for Honored Contributor rankHonored Contributor
14 years ago

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Nothing, No load connected.

I use VOM（Volt-Ohm-Milliammeter）to the measue the Voltage. And the output with pulse, I suspect the pulse cause the VOM（Volt-Ohm-Milliammeter）measurement not accurate. How do you think?

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HI ,

you could not use a VOM for accurate measurements of pulses. You should use a scope for that. Maybe it is easier to check your board with a simple design, which sets all the pins to high. If you still see the 1.6 V check your I/O and core voltage.

Kind regards

GPK