Editing Programmable logic device (section)

==PAL==
{{main|Programmable array logic}}

PAL devices have arrays of transistor cells arranged in a "fixed-OR, programmable-AND" plane used to implement "sum-of-products" binary logic equations for each of the outputs in terms of the inputs and either synchronous or asynchronous feedback from the outputs.

MMI introduced a breakthrough device in 1978, the [[programmable array logic]] or PAL. The architecture was simpler than that of Signetics' FPLA because it omitted the programmable OR array. This made the parts faster, smaller and cheaper. They were available in 20-pin 300-mil DIP packages, while the FPLAs came in 28-pin 600-mil packages. The PAL Handbook demystified the design process. The PALASM design software (PAL assembler) converted the engineers' Boolean equations into the fuse pattern required to program the part. The PAL devices were soon [[Second source|second-sourced]] by National Semiconductor, Texas Instruments and AMD.

After MMI succeeded with the 20-pin PAL parts, [[AMD]] introduced the 24-pin [[22V10]] PAL with additional features. After buying out MMI (1987), AMD spun off a consolidated operation as [[Vantis]], and that business was acquired by [[Lattice Semiconductor]] in 1999.