I have two unsigned 8-bit binary numbers
[7:0]m=00110101
[7:0]n=01101010
I found that the result of m-n is 111001010
Can someone explain the arithmetic involved?
is there any way to identify the sign of the result?
or in other words can I find which number(m or n) is higher in magnitude using the result of (m-n) operation ?(I don’t want to use a magnitude comparison operator < or > )
In reply to svishnu:
The sign of the result of (m-n) is unsigned - there is no sign. You cannot find out which has the large magnitude without extra logic. You need to explain why you cannot use the relational operators < or >, which is the easiest.
This is all explained as unsigned overflow.
In reply to dave_59:
Hi Dave, thanks for your answer.
I am currently using an 8-bit magnitude comparator(>=) in my design. I think this will infer a bulky combinational logic in the hardware. I was wondering whether I can replace this with some other logic, such that it will infer a simpler logic in the hardware.
In reply to svishnu:
To start, just use a comparator and let the synthesis tool do its job. It’s more human-readable and shows your intent. Later on if the comparator is causing area or timing issues, then you can try a more custom approach.