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Altera_Forum
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11 years ago

How to implement a 32K lookup table in CPLD?

hello, I'm newbie in VHDL, FPGAs and CPLDs devices. I would like some help for implement a lookup table with 2048 words (2 bytes). The table should be: 2048x16bits (32K), I mean, 11 bits address...
Altera_Forum's avatar
Altera_Forum
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11 years ago

Hi!

Considering you *almost* managed to fit it in a 240LE MAX II, I'm guessing that there's a LOT of identical data in there. Trying to cram that much data into a CPLD is pushing it and I'd look at other angles, like what your data will contain and if you can (potentially) compress it or access it smarter. I.e. if half of your rom is all zeros then you can significantly reduce the combinatorial amount used.

With regards to the MAXII, it's got 8K(bits) of eprom IIRC but that's slow as hell, so that's probably not going to be of any use.

-Mux