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FPGA pins

FPGAs tend to have lots of pins... So to make it a little simpler, let's put them into two bins: "user pins" and "dedicated pins".

User pins

The user pins are called "IOs", or "I/Os", or "user I/Os", or "user IOs", or "IO pins", or ... you get the idea.
IO stands for "input-output".

Dedicated pins

The "dedicated pins" are hard-coded to a specific function. They fall into the three following sub-categories.

The power pins fall into two categories: "core voltage" and "IO voltage".

An FPGA has many VCCIO pins that may be all powered by the same voltage. But new generations of FPGAs have a concept of "user IO banks": the IOs are split into groups, each having its own VCCIO pins. That allows using the FPGA as a voltage translator device, useful for example if one part of your board works with 3.3V logic, and another with 2.5V.

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This page was last updated on May 21 2013.