GAL is a device designed by Lattice on the basis of PAL, that is, a universal array logic device. For the first time, GAL adopts EEPROM process in PLD, which makes it have the characteristics of electrically erasable repetitive programming, and completely solves the problem of one-time programmable fuse type programmable devices.
GAL adopts PAL's and array programmable or array fixed structure in the \"and-OR\" array structure, but greatly improves PAL's I\/O structure and adds output logic macro unit OLMC to the output part of GAL. Because GAL is designed on the basis of PAL, it maintains compatibility with a variety of PAL devices, can directly replace a variety of PAL devices, and facilitate application manufacturers to upgrade existing products, so it is still widely used.