FPGAs can be used to chain multiple logic gates together in a compact manner. They come with 4 I/O ports and 10 internal registers, which can then be connected with each other to form logic circuits. They work fine in unloaded blocks.<br /> Supported gate types: <b>AND</b>, <b>OR</b>, <b>NOT</b>, <b>XOR</b>, <b>NAND</b>, <b>XNOR</b>, <b>Buffer</b> (=)<br /> I/O ports: <b>A B C D</b>; Registers: numbered <b>0</b> to <b>9</b>