logical and operation

[sun_ray]

Suppose an operand in more than 1 bit in a logical AND operation. Is it that operand if the operand is not equal to zero then it is equivalent to logical 1? So in that case if the operand in 01 it will evaluate to 1, if the operand in 100 it will evaluate to 1, if the operand in 00101 it will evaluate to 1, if the operand in 00 it will evaluate to 0. Please let me know whether I am correct or not in all this examples.

 

[dave_59]

Yes, you can think of it that way. A logical and (&&) operation is the same as a bit-wise and (&) when its operands are only 1-bit wide and the result is always 1-bit wide.

 

[sun_ray]

Yes, you can think of it that way. A logical and (&&) operation is the same as a bit-wise and (&) when its operands are only 1-bit wide and the result is always 1-bit wide.

The reason I raised this thread because in Samir Palnitkar's book the following has been written for logical AND :

"If an operand is not equal to zero, it is equivalent to a logical 1 (true condition). If
it is 01equal to zero, it is equivalent to a logical 0 (false condition). If any operand
bit is x or z, it is equivalent to x (ambiguous condition) and is normally treated by
simulators as a false condition."

How does he write " If it is 01equal to zero, it is equivalent to a logical 0 (false condition) " in the above quotation. Do not you think that this statement should be like this: 'If it is 01equal to one, it is equivalent to a logical 1'. Please write what you think.

 

[dave_59]

Not sure what "01equal" is supposed to mean.

 

[VishwanathAmbli]

01 is nothin but decimal 1 wch is not zero, so the statement is true...

if a number has sm value other dan zero.... n if u write a statement like if(num) wr num is any value except zero... this results in true :

 

[sun_ray]

if a number has sm value other dan zero.... n if u write a statement like if(num) wr num is any value except zero... this results in true :

What do 'sm', 'wr' stand for? Please let us know the full form so that we understand what you wrote.

01 is nothin but decimal 1 wch is not zero, so the statement is true...:

Please read the statement again. The statement is saying 01 is logic zero. Is not it?

 

[VishwanathAmbli]

some and where... n i didn't get ur statement "Please read the statement again. The statement is saying 01 is logic zero. Is not it?"
which statement u want me t read again??? specify it

 

[sun_ray]

some and where... n i didn't get ur statement "Please read the statement again. The statement is saying 01 is logic zero. Is not it?"
which statement u want me t read again??? specify it

I want you to read this quoted statement again "If it is 01equal to zero, it is equivalent to a logical 0 (false condition).".
This quotation is a part of the above quotation which I took from Samir Palnitkar's book.


Can you please answer the question that I asked you?

 

[godfreyl]

Please write properly so that we can understand your meaning.
"t", "n", "ur", "wch", "dan", "u", "wr" and "sm" are not words in the English language.

 

[dave_59]

sun_ray

I do not understand the sentence phrase "If it is 01equal to zero". What is the word "01equal" supposed to mean? This seems like a typo in the book.

In any case, truth is defined as non-zero (operand != 0) and false is defined as zero (operand == 0) for the logical operators. The result of a logical operator is 1'b1 for truth, 1'b0 for false, and 1'bx for unknown.

 

[sun_ray]

dave_59

I wrote the quotation directly from that book (soft copy). So I also do not know what "If it is 01equal to zero" or "01equal" means clearly and hence posted the thread.



Do you have documents on clock domain crossing issues? Can you please point me to some good websites on CDC issues and FIFO depth calculation?


Thanks