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Altera_Forum's avatar
Altera_Forum
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14 years ago

Unused CPLD Pins

I have two CPLDs on my PCB that connect to a common SPI bus. In order to keep things simple I'm trying to talk to only one of the chips at first but I'm having some trouble with the voltages which le...
Altera_Forum's avatar
Altera_Forum
Icon for Honored Contributor rankHonored Contributor
14 years ago

I have a further question. Suppose one solders a brand new chip onto the PCB. What state would it's pins be in? I am, of course, asking before the chip is programmed at all.

I ask because one of the chip's pins are connected to pull up resistors. If the default state is an output then powering up a brand new chip might cause some I/O damage - but if that is the case, how is one supposed to program it?