OT: Electronics word

"just logic", or "digital logic" (technically speaking a microprocessor itself is a digital logic device, so a microprocessor running code must be, too - but you see what it means).
Reply to
Tim Wescott
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Quick question. Is there an adjective for describing a digital
electronic circuit that uses ICs but no microprocessors? I thought there
was, but I can't remember it.
Chris
Reply to
Christopher Tidy
I agree with "logic" or "digital logic". Such circuits are comprised of logic chips -- CMOS logic, TTL logic, etc etc. from one or more compatible logic "families".
A microprocessor is different than a logic chip because it requires a program to define its function. A processor or computer can certainly be contstructed using logic chips but it will also necessarily contain memory and would then be regarded as a system or at least subsystem.
Reply to
Don Foreman
Another possibility...
SSI Small scale integration MSI Medium scale integration LSI Large scale integration (usually means a microprocessor)
Reply to
CaveLamb
Are you thinking about "Combinatorial Logic?" That refers to non- clocked pure functions like AND, OR, NOT, etc. which can be combined to create outputs which are functions of the inputs, like adders.
Reply to
rangerssuck
I've never heard such a term. Anyway the distinction isn't sharp because there are simple programmable devices like PALs, and computers were once built from gates. At Unitrode I watched the amount of logic in their analog power control ICs slowly increase until it covered most of the schematic. It's hard to draw a line at say the inclusion of an ALU and microcode because rudimentary versions of them can appear in custom logic that is considerably short of being a microprocessor. Today your power supply regulator or Lithium battery pack could include a stripped down dedicated processor.
I've designed circuits with Xilinx FPGAs and a VLSI ASIC that ranged from a simple bus address decoder to a custom dynamic RAM controller with state-machine memory and decision-making capability, specifically which competing access request to answer next without forgetting the refresh. Those user-programmable circuits which are like huge PALs with memory straddle the fence; they can perform logical computations if you want them to.
AFAIK insiders talk in specifics and outsiders seek generalized terms to categorize. Do we distinguish between a hobbyist who works only in wood and one who also shapes and cuts metal occasionally? Does sawing off a nail count?
jsw
Reply to
Jim Wilkins
Except that these days you can slap an FPGA on a board, put a configuration file in it, and common usage will call it 'logic' -- even though the FPGA has memory in it. Sometimes, even though the FPGA configuration has a microprocessor hidden in it.
The lines are blurred.
(Note that I am only commenting on usage as I've heard it: were I a linguist I would claim that a language is what is spoken, not what the people in ivory towers say _should_ be spoken).
Reply to
Tim Wescott
Tim Wescott fired this volley in news:vY2dne5AlKWF4w7RnZ2dnUVZ snipped-for-privacy@web-ster.com:
True, but a couple of common terms for such a board are "dedicated logic" and "combinatorial logic".
LLoyd
Reply to
Lloyd E. Sponenburgh
I began with gates made from 2N104 transistors, some in birdcage assemblies. A complex machine like a phase-shift modem was the size of a dishwasher, filled with cards containing two gates each. The designers really earned their pay back then, modern stuff is more complex but less clever.
So few of us made it all the way through school that the Army gave up on training techs for component-level troubleshooting of that equipment. The four (of ~100) in my graduating class all had science degrees.
jsw
Reply to
Jim Wilkins
Glue logic is usually describes the gates between a microprocessor and something else. I'd use the term "random logic" (kind of an oxymoron) to describe a logically functioning set of parts without a processor.
Reply to
Jim Stewart
A gate array, field programmable or not, certainly is a logic circuit.
Especially in a case like this, where common usage evolves fairly rapidly.
Reply to
Don Foreman

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