A read-only device that is a generalized combinational circuit and may include a sequential circuit. By means of connections on a semiconductor device, the PLA usually provides a ‘programmable’ sum of products function that feeds an output register, and sometimes an internal register. When the internal register is used to provide part of the input variables, the PLA is a sequential circuit; otherwise it is a combinational circuit.
The product terms in the function can be thought of as representing values that are to be acted upon when they occur; thus the PLA is a form of fixed associative memory or a specialized table lookup device adapted to the situation when the truth table has sparse entries.
Since the PLA is made specific only by the interconnections, it represents a general-purpose building block that requires changes in only one or two steps of the production process to provide different functionality. PLAs can be programmed at the time of manufacture; alternatively they may be programmed by the user, and are then called field-programmable. See also programmable device.
A logic circuit that is a sum-of-products device – input devices AND gates, output devices OR gates – where the input variables to the AND gates are programmable (as in PAL devices), and the inputs to the OR gates are also programmable (see diagram). Crosses in the diagram indicate connections of input variables (A, B, C) to inputs of AND and OR gates.
Generalized PLA
- SO
- SOA
- SOAP
- soap
- soapstone
- SOAR
- Soave–Redlich–Kwong (SRK) equation of state
- Sobieski, John
- Sobrero, Ascanio
- SoC
- socage
- social action
- social app
- social area analysis
- social behaviour
- social benefit
- social bookmarking
- social capital
- Social Chapter
- social charges
- social choice
- social choice theory
- social cleavage
- social cohesion
- social constructivism