. There are a ton of free and educational soft cores from which to learn. If, after studying this material for a while, you have more questions, by all means come back to comp.arch.fpga.
I think it is one that is constructed with programmable logic using the normal programmable logic tools. This is in contrast to a hard-core processor, which is laid out in a more custom manner. Hard core processors can be present on an IC with programmable logic, but it is inserted as a single large piece of logic, rather than build with the standard programmable parts.
Soft core is more flexible, but hard core has better performance: size, speed, low power.
I suppose you either design your own with standard logic components or license an existing a design. I believe there is one processor design with some sort of free licensing.
I added comp.arch.fpga to the group list. This should bring in some more knowledgeable folk.
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