Databases
StackOverflow2013
Postsdbo
POnegative numbers floating point subtraction circuit
Body
 

Note that there are some explanatory texts on larger screens.

plurals
  1. POnegative numbers floating point subtraction circuit
    text
    copied!<p>probably wrong place to ask but I will try.<br> I have to design a circuit that would add/subtract floating point I tried to do it using signed magnitude numbers in IEE 754 standard. They are quite large so I decided to start with something smaller just to prove the concept.<br> I found a few algorithms on the net for performing addition and substraction of positive numbers.<br> Most look like this: <a href="http://meseec.ce.rit.edu/eecc250-winter99/250-1-27-2000.pdf" rel="nofollow">http://meseec.ce.rit.edu/eecc250-winter99/250-1-27-2000.pdf</a> . <br>They do not explain what happens with the sign bit. Now I'm very confused. According to what I've found on the net there is no difference in performing:</p> <pre><code>A-B and A- (-B) </code></pre> <p>could someone help me with a link where the algorithm is explained in detail?</p> <p>thanks for all answers I've found this algebraic explanation useful <a href="http://howardhuang.us/teaching/cs231/08-Subtraction.pdf" rel="nofollow">http://howardhuang.us/teaching/cs231/08-Subtraction.pdf</a> <br> Currently my circuit performs A+B (disregarding sign bit) and A-B just like kfmfe04 wrote. I'm XORing B's input and adding 1 so I getting the result in 2C.<br> The second pdf suggests including the sign bit in add/sub operation. I will try this in the morning.<br> Having spent so many hours exercising my brain I feel a bit tired and can't think straight. Now I just wonder if I should change my circuit so that:<br> The toggle add/sub button still XORs the B [a+(-b)] but also before this part I XORs the mantissas' with their sign to convert them into 2c. <br>This way I could cover the case of negative numbers subtraction (-A)-(-B).<br> Sounds to complicated though.</p>
 

Querying!

 
Guidance
An individual column

Larger individual text columns get their own page to allow for proper reading.

SQuiL has stopped working due to an internal error.

If you are curious you may find further information in the browser console, which is accessible through the devtools (F12).

Reload