Continue to Site

Welcome to EDAboard.com

Welcome to our site! EDAboard.com is an international Electronics Discussion Forum focused on EDA software, circuits, schematics, books, theory, papers, asic, pld, 8051, DSP, Network, RF, Analog Design, PCB, Service Manuals... and a whole lot more! To participate you need to register. Registration is free. Click here to register now.

Register Log in

help me to understand the equations

Status
Not open for further replies.
L

lihui002

Newbie level 5
Newbie level 5
Joined
Nov 4, 2005
Messages
10
Helped
2
Reputation
4
Reaction score
1
Trophy points
1,283
Activity points
1,378
There are two equations for the adder or subtraction a book

s=a^(b^M)^c;
c[i+1]=(a+c)(b^M)+ac;
when M = 0, it is an adder a[i[+b
when M = 1, it is a subtraction a-b
-------------------------------------

I think when M = 1, d=a^b^l, the b should not become the 1's complement,
and l[i+1]=(a^M)(b+l)+bl, a should be the 1's complement, not the b.

please explain the equation in the book.

Thanks
 

because
a-b=a+(~b+1)
maybe you forget add 1
 

but b^1 is ~b, not ~b+1.
please explain more particular, thanks
 

sorry, what I said is not clear,
when excute sub
M=1,at the same time c[0]=1
when excute sub
M=0,at the same time c[0]=0
c[0] must be assigned previously
 

I think M=0 , a+b+c
M=1, a-b-c,
so the c not equal M.
 

I never said c equals M
what i said is c[0] equals M
maybe you can try to check it through simulating the code
 

    L

    lihui002

    Points: 2
    Helpful Answer Positive Rating
I have run the simulation with code, through the simulation result,
s = a ^ b ^ c;
c[i+1] = (a^M)(b+c)+bc;
should can get the correct result.

but arithmetic in the book, the result is not right.

Thanks you suggestion
 

Thanks tarkyss, now I understand your means.
 

Status
Not open for further replies.

Similar threads

Part and Inventory Search

Welcome to EDABoard.com

Sponsor

Back
Top