PGA - sometimes it is "Programmable Gate Array" some times "Pin Grid Array" (former is a chip architecture the latter is package type) On the contrary, it is a reaction to that. The first time I was exposed to programmable logic it was with "PAL"s. These are fuse programmed and-or-invert gates tied to an array of interconnects. The term PAL was trademarked by the parent company (whose name escapes me at the moment MMD?, but AMD bought them) and so the generic term was "PLA" (programmable logic array). When the networks within the chip became more complex they weren't really "arrays" anymore and so the generic term for a logic device that could be programmed was "PLD" (programmable logic device). This included memories with programmable chip select logic on chip, and traditional PLAs etc. Erasable devices were called EPLDs. Then "Gate Arrays" became dense enough to be practical and the chips were referred to as "ASICs" (Application Specific ICs) or Gate arrays, or programmed gate arrays (PGAs) but the last was confusing with the package type. Then gate arrays that could be programmed in the field (versus mask programmed) made their debut and they were called Field programmable gate arrays (FPGAs). Devices that were still logic cells that could be combined but had higher densities are called Complex PLDS or CPLDs. --Chuck

Chuck wrote: MMI, Monolithic Memories Inc. PLA predated PALs by many years. The PAL is a *less* flexible version of a PLA. In a PLA, both the AND and OR matrices are programmable. In a PAL, only the AND matrix is programmable. The OR matrix is fixed. For instance, a PAL16L8 has eight OR gates (with output inverters, so they're effectively NOR), but each OR gate has exactly eight AND terms. In a PLA, there are a large number of AND terms, which may each be wired to any combination of the OR gate inputs, and may be connected to more than one OR gate. Many later PLDs (Programmable Logic Devices, a fairly generic term) have added flexibility to the OR matrix, allowing some amount of product term sharing. But generally they have not gone back to the same degree of flexibility as the PLA.

Rumor has it that Eric Smith may have mentioned these words: [Big Ol' Snip] I have a question: How many people here *hate* the term OTP-EPROM? EPROM as most people here know is Erasable Programmable Read Only Memory... but an OTP-EPROM is short for One Time Programmable Erasable Programmable Read Only Memory Basically, it's an FAMOS-based EPROM chip in a plastic package and can be programmed by a regular EPROM programmer - but as it's got a plastic package, it can't be erased or reprogrammed (hence the addition of OTP) - If it can't be erased or reprogrammed, why not just call the damn thing a PROM?????????????????? Just one of those stupid things I think about... Roger "Merch" Merchberger -- Roger "Merch" Merchberger --- sysadmin, Iceberg Computers Recycling is good, right??? Ok, so I'll recycle an old .sig. If at first you don't succeed, nuclear warhead disarmament should *not* be your first career choice.