Programmable logic array 可程式逻辑阵列
A programmable logic array (PLA) is a kind of programmable logic device used to implement combinational logic circuits. The PLA has a set of programmable AND gate planes, which link to a set of programmable OR gate planes, which can then be conditionally complemented to produce an output. It has 2^N AND Gates for N input variables and for M outputs from PLA, there should be M OR Gates, each with programmable inputs from all of the AND gates. This layout allows for a large number of logic functions to be synthesized in the sum of products (and sometimes product of sums) canonical forms.