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0 pointsalexpotato3y ago0 comments

CS degree holder here who had many CE/EE friends who switched from CE/EE to CS (Rutgers University).

One thing that used to blow my mind was the difference between logical circuit design in CS vs CE/EE.

E.g. if the task was "Build a circuit to do X logic using these components AND, OR, XOR etc"

- In CS, it was " Please use the common shapes for each component"

- In CE/EE, it was "Please use the EXACT part code for EACH and EVERY component you use!"

I remember thinking: "Isn't the key lesson to learn the logic flow design vs being able to lookup each and every party number?? Is the EE department trying on purpose to get rid of people?"

You could make the argument that forcing people to do the detail but boring work is a good filter for people who are REALLY serious about EE but I would argue that there have to be better ways to do that.

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notch656a3y ago

It's not 'looking up the part code' it's identifying components that have level and drive compatibility, fanout and timing requirements met, acceptable internal and parasitic inductance/capacitance/resistance. Checking if the nets are still theoretically a wire and not a transmission line, that ringing isn't degrading intended application, that the final output of the logic can actually drive the output of the logic diagram. Ensuring the lead time, footprint, cost, and supply chain are all compatible with your manufacturing process and planning.

If you just use theoretical perfect lossless and timeless components you completely miss and forget about a huge portion of EE which is not just designing the logic but actually implementing it in reality. It sounds like the EE program was setting people up to take the real world and imperfections into account while the CS version of the same course makes the valid assumption an electrical engineer has already provided the hardware platform so you can focus on the logical implementation.

>Isn't the key lesson to learn the logic flow design

In CS yes, in EE no. In EE that is only one of many key lessons, and without interlocking with other key lessons necessary to pick the real world components you end up with a circuit that either works purely out of luck, only in low-speed designs in noiseless environments, or not reliably.

philwelch3y ago

Do individual logic gates even have part numbers anymore? In my EE labs in college we had FPGA’s.

bobsmooth3y ago

Here's a 4 channel OR gate

https://www.digikey.ca/en/products/detail/texas-instruments/...

But my logic labs were also done on FPGAs.

raverbashing3y ago

"Kids these days" ;)

Yes, I think now it's mostly the 74AHC, 74ALVC, some 74ALS/74HC families (maybe others) Depends on the application https://en.wikipedia.org/wiki/7400-series_integrated_circuit...

(using the fpga is fine, but I'd probably want to focus on the circuit itself ant not something like VHDL at first)

philwelch3y ago

To be clear, this was a 200-level EE class that was, at the time, also part of the CS curriculum. One of my favorite classes, at least in retrospect.

The professor was simultaneously the founder of a company that made FPGA boards for EE students. They also made a little microcontroller board that was basically Arduino before Arduino; we used that in another class where we made robots and programmed them in AVR assembly.

Unklejoe3y ago

They're still used sometimes for low level ancillary board functionality. Like, controlling reset lines going to SoC's, etc.

It's actually something that an EE may end up using in their career quite often if they're doing board design.

Though, we normally use CPLDs for that kind of stuff now, but if you can get away with a few logic chips, maybe it can simplify the design.

smilekzs3y ago

BTW these hardware glue logic is often done with e.g. TI LittleLogic series (i.e. 74LVC1/2Gxx) where you can use a tiny package for a tiny function otherwise not integrated into big chips.

j / k navigate · click thread line to collapse

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notch656a3y ago

>Isn't the key lesson to learn the logic flow design

philwelch3y ago

Do individual logic gates even have part numbers anymore? In my EE labs in college we had FPGA’s.

bobsmooth3y ago

Here's a 4 channel OR gate

https://www.digikey.ca/en/products/detail/texas-instruments/...

But my logic labs were also done on FPGAs.

raverbashing3y ago

"Kids these days" ;)

Yes, I think now it's mostly the 74AHC, 74ALVC, some 74ALS/74HC families (maybe others) Depends on the application https://en.wikipedia.org/wiki/7400-series_integrated_circuit...

(using the fpga is fine, but I'd probably want to focus on the circuit itself ant not something like VHDL at first)

philwelch3y ago

To be clear, this was a 200-level EE class that was, at the time, also part of the CS curriculum. One of my favorite classes, at least in retrospect.

Unklejoe3y ago

They're still used sometimes for low level ancillary board functionality. Like, controlling reset lines going to SoC's, etc.

It's actually something that an EE may end up using in their career quite often if they're doing board design.

Though, we normally use CPLDs for that kind of stuff now, but if you can get away with a few logic chips, maybe it can simplify the design.

smilekzs3y ago

BTW these hardware glue logic is often done with e.g. TI LittleLogic series (i.e. 74LVC1/2Gxx) where you can use a tiny package for a tiny function otherwise not integrated into big chips.

j / k navigate · click thread line to collapse