Difference between LUT and MUX

[Muthuraja.M]

Hi friends,

I need to know the difference between the LUT and ROM.

Please clarify the answer related to FPGA.

 

[TrickyDicky]

Do you want the difference between lut and mux? or lut and ROM?

In terms of FPGA, a lut refers to the small programmable devices (really just ROMS) that create the logic in the design.
A ROM would be a memory device made using integrated RAMs or many LUTs.

 

[Muthuraja.M]

Thanks for ur reply TrickyDicky

Tell me the similarities between LUT and MUX.

Are they both same ????

 

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LUT - stands for Look Up Table, it's a ROM so you have an address that outputs values for each address so you can produce any function of n-inputs (addresses) at the output of the LUT.
A MUX is used to select one input out of 2^n inputs using the n-input select. You can hook the inputs up to constants that produce the same function of an n-input LUT. So a mux can be made to behave just like the LUT.

 

[Muthuraja.M]

So the basic function of LUT, MUX and ROM have same rite... But it makes it different where it is used rite ??

In FPGA wat is a LUT, MUX and ROM..

Thanks for ur reply ads-ee...

 

[TrickyDicky]

No, a mux and a rom/lut are different

A Rom/lut is a memory. It has N address locations. The input is an address to output the value stored at the specified location.
a Mux is a logic device. It has N inputs, and a select input that selects which of the N outputs is connected to the output.

 

[Muthuraja.M]

Thanks for ur reply trickydicky..

I had understood the differences between LUT/MUX and ROM