• nickwitha_k (he/him)@lemmy.sdf.org
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      17 hours ago

      Top row, second column. That chip is a Xilinx (now AMD) Spartan 6 Field-Programmable Gate Array (FPGA). An FPGA is a type of chip that contains an array of logic gates, flip-flops, and other elements whose interconnects can be “programmed” (I use quotes because it’s more like configuration than software programming). These elements are collectively referred to as the FPGA “fabric” and the naming of the individual elements varies between manufacturers but Xilinx uses “Logic Cells”.

      The fabric of this particular chip has 74,637 Logic Cells (there’s more element types but I’m not going into those because I’m still learning any them).

      What makes FPGAs so special? Basically, they contain all of the parts needed to make a CPU (or other digital circuit). An FPGA may not be able to implement a general purpose CPU that is as fast or powerful as custom silicon but, it can do it. A CPU implemented on an FPGA is known as a “soft core”.

      What is RV32? Simply, a 32-bit RISC-V processor. There are some open-source RV32 implementations that will both fit in the pictured FPGA and are capable of booting mainline Linux.