Assign statement with less than or equal ....

Status
Not open for further replies.
M

Muthuraja.M

Advanced Member level 4
Joined
Jul 20, 2013
Messages
101
Helped
0
Reputation
0
Reaction score
0
Trophy points
16
Visit site
Activity points
634
Hi all,

I want to know the operation of the below assign statement.

assign carry = (ai+bi+di) >= 2;

This assign statement is used to compute carry operation in full adder.

How this statement gives the carry as output . pls explain me....

Thanks in advance ....
 

assign carry = (ai + bi + di)>=2 ? 0 : 1;

used "?" operator, "<condition> ? <pass condition> : <failled condition>;
 

i dont understand ur answer rca pls explain with any two examples the bits containing carry as 1 and 0 respectively..

a = b= d = 1

and

a=1 , b=d=0

pls explain with these two examples....
 

"?" is a verilog operator, google or verilog book will explain that as:

assign toto = <condition> ? <pass condition> : <failled condition>;

toto could be write by <pass condition> or <failled condition> function of the <condition> result.
 

i know about the conditional operator . But i want to know that how did u say that the statement that is posted by
me is conditional operator assignment .


That wat i need to know rca...
 

Muthuraja.M

rca should have said the assignment you posted is equivalent to a conditional operator.

assign carry = (ai + bi + di)>=2 ? 0 : 1; // does the opposite of what you wanted
assign carry = (ai + bi + di)>=2 ? 1 : 0; // is equivalent to what you posted assign carry = (ai+bi+di) >= 2;
 

why we use 2 over there is that 2 is in binary or decimal number .

i want that only ...
 

The 2 is decimal, binary can only have the digits 0 & 1.

assuming ai, bi, and di are all single bit values then the result of ai + bi + di will be a 2-bit value. so 2'b00 & 2'b01 will result in carry = 1'b0 and 2'b10 & 2'b11 will result in carry = 1'b1.

Regards
 

ok i understand ...

thanks rca and ads-ee.

But how the 1st bit only takes as carry .
 

the <pass condition> and <fail condition> is single bit.
 

Status
Not open for further replies.

Similar threads

Menu
Log in
Register
Cookies are required to use this site. You must accept them to continue using the site. Learn more…