BRAM and applocations

Hello Dears
Could you please explain, what is the deference between BRAM and LUT in fpga? In fact when and where you, as a designer, apply BRAM or LUT in your design?
Regards
Mostafa

Dear Mostafa,

FPGAs comprise different types of configurable blocks, two of them being BRAMs and LUTs. Basically, LUTs are "function generators", in the sense that they can implement any desired Boolean function: in most recent Xilinx FPGAs LUTs have 6 inputs, meaning that they can implement any 6-inputs Boolean function, while in least recent Xilinx FPGAs they had only 4 inputs. Thus, LUTs across the device store the configuration bits that bring up the Boolean functions that make your functionality. BRAMs, on the other hand, are memory blocks typically used for storage purposes. However, LUTs can also be used as memory storage, the choice depends on several factors: area, performance, power.

If you are interested in understanding FPGA structure you should get a look at Xilinx user-guides of a particular FPGA family (e.g., from the Xilinx website you can freely download Virtex-5 FPGA user guide that explains every part of an FPGA and how to use it).

Cheers

Thanks a lot dear kingslayer for your comment.