Velocity Reviews - Computer Hardware Reviews

Velocity Reviews > Newsgroups > Programming > VHDL > Beginners questions for addition

Reply
Thread Tools

Beginners questions for addition

 
 
Clemens Bosch
Guest
Posts: n/a
 
      12-02-2004
Hello

I have the following problem: I want to perform an addition in one clk
cycle, therefore I have implemented a modul add which performs me this
bitwise. I have got an input vector whereas bit I contains the bits for
operand a, whereas I+1 contains the bits for operand b. Therfore first of
all I want to extract the values and save it in a signal a, respectivly b
which is then the input for my adder. Before I add it I want to shift signal
a by 4 positions. Here is the way I thought it would work:

signal a,b,term1: std_ulogic_vector((width-1) downto 0) := (others => '0');

begin

combrocess(inp)
variable av, bv: std_logic_vector((2*width-1) downto 0);

begin
for I in 0 to (width-1) loop
av(I) := inp(I);
bv(I) := inp(2*I);
end loop;
a <= av;
b <= bv;
end process;

term1 <= a(width-5 downto 0) & "0000";

add1: for I in 0 to (width-1) generate
add1_I:add port map(a(I),b(I),result(I));
end generate

So I have to do it this way, that the values are extracted first and stored
in a variable for later tasks. I cant feed them directly to the adder. So
can perhaps someone explain a good way to solve this problem? I just want to
extract the values as soon as the input changes, and then this values have
to be shifted before the are put into a adder chain and this should somehow
be performed in one clk cycle.

Thanks for every hint
Clemens



 
Reply With Quote
 
 
 
Reply

Thread Tools

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
2x beginners questions Chris Bradshaw C Programming 3 02-24-2011 01:26 AM
a few beginners questions .... Thomas Java 11 07-11-2007 02:45 AM
A few beginners questions wannaberor Ruby 14 04-22-2007 09:28 PM
Two questions...first, outputting strings from a datafile, and string addition... snow.carriers@gmail.com C++ 3 03-02-2006 04:01 PM
Beginners questions: Using EJBs on two Workstations bebonights Java 0 10-13-2003 02:28 PM



Advertisments