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DLA adder fun! - Printable Version

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DLA adder fun! - Konstacon - 08-21-2013

As you may know, me and block were talking about "DLA". You were probably like "Wtf is DLA!" but here you will not ask that again! DLA stands for Decoder Lookup Adder. It uses decoders to decode all possible inputs, and encodes it into the output. At first it was called ILA for Ineffeciant Lookup Adder. Block made the first design, it was a speed of 9.5 ticks! I knew I could improve, so I jumped in and made a 4 tick ILA. I thought it wasn't ineffeciant, so I named it DLA. It was quite big, but did the job. Want to see a DLA? Ask me! Thanks, snug.

Also, props to block for making ILA.


RE: DLA adder fun! - BlockandCube - 08-21-2013

ILA was meant as a joke, you know, but DLA is turning out to be awesome.


RE: DLA adder fun! - newomaster - 08-21-2013

Make a DLA ripple carry adder that uses decoders to calculate sum and cout per bit as a normal ripple carry adder would, and then ripple them to make an (probably not efficient) interesting adder.


RE: DLA adder fun! - Iceglade - 08-21-2013

Hmm... that would actually be kind of cool, and not nearly as huge as the original idea of say, a 16-bit DLA (which is obviously pretty much impossible). I'm going to personally try it right now Tongue


RE: DLA adder fun! - Konstacon - 08-21-2013

(08-21-2013, 03:00 AM)newomaster Wrote: Make a DLA ripple carry adder that uses decoders to calculate sum and cout per bit as a normal ripple carry adder would, and then ripple them to make an (probably not efficient) interesting adder.
I have done that, I can build one if you want, but it is REALLY big for 8 bit. But it still works. Tongue


RE: DLA adder fun! - WrytXander - 08-23-2013

So supposing you have pretty good decoders, I am not sure if what I am going to say is possible but, make a full adder completely out of decoders. Which would have inputs: A, B, Cout and outputs Sum Cin. (Ofcourse Big Grin) and than just hook up to carry outs / carry ins. Is that ready what you are doing? Since you could have a cell based DLA, and like a giant all-possible-combinations adder.


RE: DLA adder fun! - newomaster - 08-24-2013

Here's a decoder adder I made. Basically it just decodes every possible combination of adder inputs and outputs the correct values for sum and carry out. It's very slow and inefficient (3 tick ripple blah), but whatever it was fun to make :3
[Image: 99zoitD.png]


RE: DLA adder fun! - Iceglade - 12-07-2013

Hate to be the guy to bump threads... but thought I'd might as well considering I saw Newo's, and went ahead and made a 2 tick carry design. This is technically better than normal RCA due to the fact that each operation is 2 ticks, including direct throughput to the adder. Whereas in a normal RCA, each XOR is 2 ticks, combining into 4, the decoder logic remains at 2 in my design.

How about we call it LTC (lookup table carry)? Big Grin

[Image: 25XSTsO.png]

TL;DR: Better direct throughput by combining the half adders.


RE: DLA adder fun! - Chibill - 12-07-2013

I will start work on my 8 bit 10 tick decoder again for this.


RE: DLA adder fun! - Iceglade - 12-08-2013

You will never need more than a 3 bit decoder for LTC.


RE: DLA adder fun! - Ntwede - 12-10-2013

My new ALU uses a DLA to count how many 1's are in a number. for example, the number 7 in binary has 3 1's (111) and 12 woul dhave 2 (1100). They're awesome.


RE: DLA adder fun! - Chibill - 12-11-2013

I can do this with 2 bit decoders and it may be 1 tick. Then the encoding.