I believe two's complement should be thought of as a way to represent numbers in binary and not as a process (which some websites and folks appear to do).

Wikipedia gets this correct. Two's complement is the most common method of representing signed (positive, negative, and zero) integers on computers. 

However, the entry goes on to state that "The following is the procedure for obtaining the two's complement of a given negative number in binary digits". This incorrectly views two's complement as a procedure or a process, which is ambigious at best. What is actually described is the process to obtain the negative of a number that is represented in two's complement. Thus it should state ... "The following is the procedure for obtaining the negative of a number in two's complement representation".

Some websites like https://www.allmath.com/twos-complement.php make this same mistake, whereas others like https://www.exploringbinary.com/twos-complement-converter/ get it right.

There is a process in HW that converts a two's complement number (positive or negative) to the negative of that number by inverting all the bits and adding 1.  This process is not taking the two's complement. of a number. Again, it is simply the process to get the negative of a number that is represented in two's complement. This allows us to turn A - B into A + (-B), so we can use a binary adder to do subtraction.

Once I flip the switch the ones place starts counting, once it reaches 9 it goes back to 0 and the tens digit goes up one. So it’s counting. Then it stops at 80. My teacher helped me connect the circuits, and then he challenged me to figure out how to get it to stop at 90 instead of 80. Honestly, I’m so bad at digital electronics, so I have no idea. Can someone please explain to me how? Or maybe there’s a better way to connect them?

Hi so I've taken it upon myself to create a 1 bit CPU (why? idk.) tbh this thing is a spaghetti monster and I don't even know what it's capable of (if anything.) I finally have finished it and whenever I use my Jump instruction Logism freaks out because of "oscillation apparent". This only happens If the jump address is less than the address it is currently on. is there a fix, or am I doomed to somehow create this in real life?

also the spaghetti mess. also attached is the instruction set.

https://preview.redd.it/3q22yus78gfe1.png?width=1345&format=png&auto=webp&s=f104d520e0f227735097fb15f853dbb30b2b2fc1

https://preview.redd.it/6w5gmze17gfe1.png?width=1322&format=png&auto=webp&s=be40e75eca042216007b7b4a4b33bca2705ef21c

simplify the boolean function f(w x y z)=Σ(0,1,3,8,9,10,11,12,13,14,15) using kmap

I was going through my textbook at stumbled upon this example. Does the critical path depend on the combination of inputs to a circuit ?

I understand that it’s the path with the longest delay in the circuit (the propagation delay), but I don’t understand how it’s supposed to be affected by a combination of inputs. Shouldn’t a gate have the same delay for all inputs ?

Hi,

I was wondering if it’s ok to remove s7 as there are no inputs to its bubble.

Hello, i am a college student and forced to take foundations of systems 1 as its in my degree plan. The main instructions are The Goal in this project is to build a counter that will count from 0 to 15 repeatedly. This will be done

using Logisim or other approved circuit simulation software. It will display the value as a binary code

using LED’s and as a numerical representation using two 7 segment displays. Please help me

I am having a hard time with this. Most of the information in the internet is about wallace tree multiplayer, but I need to build an adder.

These are my exercises Build the following Wallace tree adder

1. Adder to add seven bits
2. Adder to add three 4-bit numbers
3. Adder to add five 4-bit numbers
4. Adder to add seven 4-bit numbers

Hi,

I was going through Digital Design & Computer Architecture RISC-V edition. The answer key says that the Boolean equation for a 4 input XNOR gate can be expressed as seen in the image.

I tried many times to understand how to get to that answer and in what case that implementation would be useful, but I still have no clue.

I would appreciate if someone could shine some light on me.

I have a small control box running on +5v from a USB cable and I'd like to include a safety circuit that I suspect can best be done with a binary latch, but once a particular state is reached, I want it to stay in that state as long as it has power. It'll also have a +3.3V source, since much of this will be working on +3.3V instead of +5v.

I think the inputs would be an always-on from the power source and an input from the main switch. (There are parts that stay on whenever there is power, such as a red LED to show it's on. The main switch will turn active devices on and off.)

I am learning about flip flops and latches and do realize that something needs to be done to make sure flip flops and latches initialize to a known state. I know most flip flop and latch circuits have 2 outputs. I'm not concerned about which one to use (Q or ~Q), but I'd like to be able to do this:

Initialization state: OFF
Immediately after initialization and main switch on: OFF
Once main switch is off: ON

The idea is that when I turn the system on, the output here will be off for initialization and will be off. (So devices don't flicker on during startup.) Then, if the main switch is on (which means it was left on by mistake), the output goes low. Once the main switch is turned off (or if it's off on power-up), I want the output to go high and stay high.

I haven't seen a flip flop or latch that, once it reaches a particular state, does not change. This one would be OFF until the first time the main switch is turned off, then it would turn ON and stay ON from then on.

(The idea is that, if I lose power, and the main switch was on, when power comes back, it won't work until I turn the main switch off - OR the main switch was off for power up. This way devices won't turn on by accident if I'm not around when power is restored.)

I have a project due soon and I need to get a counter that counts down from 9-0. And it has to be the simplest one possible. I have achieved it using state machine but I believe there to be a simpler method. The best i could do for counting up is use a D-Flip-Flop ripple counter. This works well but for counting down I cant find an elegant solution. When i change the clock edge of the D-Flip-Flop ripple counter it counts down but i cant figure out how to change from 0 to 9. Any help? I am doing this in LOGISIM

In carry look ahead adder, for G and P, why is it done bit by bit and not together like G = A . B fully?? For example if A = 1010 and B = 1101, we get G0=0,G1=0,G2=0,G3=1 and even if we do it like G=1000 right, so in the end each individual bits value is going to be the same??
(Note: I implemented it in a software(xilinx vivado using verilog), it doesn't work if I AND it as a whole, it only works when I do it bit by bit.)

our house is near to the transformer like 10metres only, we get high voltage , it show in multimeter like above 270+ in mid day , in night its show 275+ , my gaming pc motherboard failed due to the high voltage( said by pc expert) , we have the inverter(ups) also ,my pc expert say like put over all main line stabilizer for your home (Our home electricity in 3 phase) except you put each stabilizer for pc and laptop you put over all main line stabilizer ,is it possible for home , if yes means how much its cost, which brand we choose please help it

https://reddit.com/link/1gn8m2f/video/fhsnlbs98vzd1/player

This is a circuit I built using some stuff I had around It is a synchronous 3-bit counter using JK Flip-flops (M74HC73) , a 555 timer for the clock pulse , some LEDs combined to create a simple 7-segment display , a custom circuit is used to translate the 3 bit binary and light up specific LED groups to display the numbers in base 10. I used an old phone charger for power supply and 74LS series AND ,OR and INVERTER ICs to build the "driver circuit".
I am a beginner in hobby electronics and just wanted to put this out there. Any suggestions are welcome.

I'm building an automatic plant waterer and it currently implements sensors for moisture, light and temperature. The project requires that I include 2-3 more parameters. Any suggestions on what could be included? I suppose pH could be one of them as well?