Fpga - Tumblr Posts
That is a very neat idea!
If you like things like that you might want to look into VHDL ( I learned that... some years ago, but have not touched it since ) or Verilog.
They are... programming languages for making logic gate logic.
You combine that with an FPGA, which is essentially a whole lot of NAND gates ( Which as I said, can represent any logic gate system ), and then you can make hardware... via software.
And yes, these essentially do things like your idea. Things that would take a CPU aaaaages to do, can be done very very fast. So you "just" have normal C code, but if it runs onto one of the problems it have hardware for, it uses the hardware.
This is also how graphics cards work, or just floating point operations!
It is insanely cool! :D
What is half-adder and full-adder combinational circuits?
So this question came up in the codeblr discord server, and I thought I would share my answer here too :3
First, a combinational circuit simply means a circuit where the outputs only depends on its input. ( combinational means "Combine" as in, combining the inputs to give some output )
It is a bit like a pure function. It is opposed to circuits like latches which remembers 1 bit. Their output depends on their inputs AND their state.
These circuits can be shown via their logic gates, or truth tables. I will explain using only words and the circuits, but you can look up the truth tablet for each of the circuits I talk about to help understand.
Ok, so an in the case of electronics is a circuit made with logic gates ( I... assume you know what they are... Otherwise ask and I can explain them too ) that adds 2 binary numbers, each which have only 1 character.
So one number is 1 or 0
And the other number is 1 or 0
So the possible outputs are are 0, 1 and 2.
Since you can only express from 0 to 1 with one binary number, and 0 to 3 with 2, we need to output 2 binary numbers to give the answer. So the output is 2 binary numbers
00 = 0
01 = 1
10 = 2
11 = 3 // This can never happen with a half adder. The max possible result is 2
Each character will be represented with a wire, and a wire is a 0 if it is low voltage (usually ground, or 0 volts) and a 1 if it is high voltage (Voltage depends. Can be 5 volts, 3.3, 12 or something else. )
BUT if you only use half adders, you can ONLY add 2 single character binary numbers together. Never more.
If you want to add more together, you need a full adder. This takes 3 single character binary numbers, and adds them and outputs a single 2 character number.
This means it have 3 inputs and 2 outputs.
We have 2 outputs because we need to give a result that is 0, 1, 2 or 3
Same binary as before, except now we CAN get a 11 (which is 3)
And we can chain full adders together to count as many inputs as we want.
So why ever use a half adder? Well, every logic gate cirquit can be made of NAND (Not and) gates, so we usually compare complexity in how many NAND gates it would take to make a circuit. More NAND gates needed means the circuit is slower and more expensive to make.
A half adder takes 5 NAND gates to make
A full adder takes 9 NAND gates.
So only use a full adder if you need one.
Geeks for Geeks have a page for each of the most normal basic cirquits:
I hope that made sense, and was useful :3