logic gates: not 1 not 0 but somthing in between, what happened??!!

Thread Starter

Just me1

Joined Sep 3, 2017
59
So. I was working on my simulated computer circuit and my simulator uses 5v as high (1) and 0 as low (0)
But for some reason im getting 2.5v
should i be worried about the real thing having that? Or is it just something in the simulation, and how do i fix it?
 

ScottWang

Joined Aug 23, 2012
7,504
This is it
The photo unclear.

If you use 5V for the cmos Vcc power supply in the real world, normally you won't get 2.5V, unless the ic is damaged.

If you want to check where is the problem then you can split the circuit as 4 parts and simulates each part to make sure which part has problem to get 2.5V.
 

Thread Starter

Just me1

Joined Sep 3, 2017
59
The photo unclear.

If you use 5V for the cmos Vcc power supply in the real world, normally you won't get 2.5V, unless the ic is damaged.

If you want to check where is the problem then you can split the circuit as 4 parts and simulates each part to make sure which part has problem to get 2.5V.
Might be the vcc, becouse my simulator doesnt use the pin and just has magic power out of nowhere
 

Thread Starter

Just me1

Joined Sep 3, 2017
59
Is this a school project?
No. But when im finished with school 2 yrs im going to do OR designing and finding and solving the problems in circuits OR be someone who fixes it ( soldering, measuring etc. ) but im not sure what i am going to choose, but that i will see in the future
 

bertus

Joined Apr 5, 2008
22,985
Hello,

I made some comments on your picture:

Just_20170905_071551_comment.jpg
Bertus

PS can you post a screenshot of the circuit, that will be sharper as a picture with your phone.
 

WBahn

Joined Mar 31, 2012
33,068
You've got several gates that have floating inputs. That is very bad in real life. How simulators handle it varies quite a bit.

It would really help if you could tell us WHICH signals on that schematic are misbehaving and what the signals are on all of the gates that feed into those signals.

Also, is this part of some big, complicated schematic that was all put together before any of it was simulated at all?
 

Thread Starter

Just me1

Joined Sep 3, 2017
59
You've got several gates that have floating inputs. That is very bad in real life. How simulators handle it varies quite a bit.

It would really help if you could tell us WHICH signals on that schematic are misbehaving and what the signals are on all of the gates that feed into those signals.

Also, is this part of some big, complicated schematic that was all put together before any of it was simulated at all?
I simulated them individually and after that i put it all together, first i had the alu with manual inputs, but now i added ram and registers, but after that i removed the ram becouse it lagged way too much for me, and im used to lag, but it is the register read function that isnt working properly, the register is the same as the ram, only 4 bits less and only 1 adress,

When i tested the register read and just about every function with logic inputs there was no problem, and after i connected it to the counter stuff went wrong
 

Thread Starter

Just me1

Joined Sep 3, 2017
59
The photo unclear.

If you use 5V for the cmos Vcc power supply in the real world, normally you won't get 2.5V, unless the ic is damaged.

If you want to check where is the problem then you can split the circuit as 4 parts and simulates each part to make sure which part has problem to get 2.5V.
You've got several gates that have floating inputs. That is very bad in real life. How simulators handle it varies quite a bit.

It would really help if you could tell us WHICH signals on that schematic are misbehaving and what the signals are on all of the gates that feed into those signals.

Also, is this part of some big, complicated schematic that was all put together before any of it was simulated at all?
You guys need to see the whole thing or the problem area?
 

Thread Starter

Just me1

Joined Sep 3, 2017
59
The problem is solved by magic, and now it could load a or b and also add and sub, no. It cannot add and sub yet. The register doesnt stay on at loading. But thats an easy fix.

Thanks for your efforts WBahn , bertus , and ScottWang !! :)
 
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