Glue logic: Difference between revisions

In [[electronics]], '''glue logic''' is the custom [[Digital circuitelectronics|logic circuitry]] used to interface a number of [[Commercial off-the-shelf|off-the-shelf]] [[integrated circuitscircuit]]s.<ref>{{cite web|title=Glue Logic|url=httphttps://www.pcmag.com/encyclopedia_term/0,1237,t=glue+logic&i=43822,00.asp|work=Definitions|accessdateaccess-date=2 January 2013}}{{Dead link|date=June 2024 |bot=InternetArchiveBot |fix-attempted=yes }}</ref> This is often achieved using common, inexpensive [[7400-series integrated circuits|7400]]- or [[4000-series integrated circuits|4000]]-series components. In more complex cases, a [[programmable logic device]] like a [[Complex programmable logic device|CPLD]] or [[Field-programmable gate array|FPGA]] might be used. The falling price of programmable logic devices, combined with their reduced size and power consumption compared to discrete components, is making them common even for simple systems. In addition, programmable logic can be used to hide the exact function of a circuit, in order to prevent a product from being [[Reverse engineering|cloned]] or counterfeited.

Typical functions of glue logic may include (but are not limited to):

*[[List of 7400 -series integrated circuits|Simple logic functions]].

*[[Address decoder|Address decoding circuitry]] used with older processors like the [[MOS Technology 6502|6502]] or [[Zilog Z80|Z80]] to divide up the processor's address space into RAM, ROM and I/O. Newer versions of these processors, (such as the [[WDC 65816/65802|WDC 65816]] or the [[Zilog eZ80|eZ80]]), may add features that enable glueless interfacing to external devices.

*Buffers to protect outputs from overload, or protect sensitive inputs from [[Electrostaticelectrostatic discharge|ESD]] damage.

*Voltage level conversion, ''e.g.'', when interfacing one logic family ([[CMOS]]) to another ([[Transistor-transistorTransistor–transistor logic|TTL]]).

[[Category:Electrical engineeringcircuits]]