12 Hour Clock problem

PAUL W. OP #5564882
Rate this post
• ▲ useful
▼ not useful 
So I’m on HDLBits trying to work out a problem for a 12 hour clock. I’ve 
tried it two different ways by now. First I’ve tried it with conditional 
statements, and the second way I tried it with case statements. The 
first time, I’m getting and issue that there are some mismatches for my 
Seconds and Minutes outputs and its also saying that the code can not 
simulate. When I do it with the case statements, I'm not getting any 
mismatches, but again it is not simulating.

With the case statement version, its saying that there is an iteration 
limit @ time 0 ps, while for the conditional version, its saying that 
there is an iteration limit @ time 38255 ps. Do I have a loop somewhere 
that I'm not seeing? I will attach both files so you can see the code. 
This is the link to the problem in question 
https://hdlbits.01xz.net/wiki/Count_clock
Attached files:
Reply Quote Edit Move Thread sperren Anmeldepflicht aktivieren Anpinnen Delete topic Thread mit anderem zusammenführen Report post
Lothar M. Moderator (Company: Titel) #5564923
Rate this post
• ▲ useful
▼ not useful 
PAUL W. wrote:
> Do I have a loop somewhere that I'm not seeing
I don't know Verilog, but this looks alike a combinatorial loop without 
no clock:
1
   assign #1 h1 = h2;

2
    assign  #1 m1 = m2;

3
    assign #1  s1 = s2;

4
    

5
    twelve z1(h1, h2);

6
    sixty z2(m1, m2);

7
    sixty z3(s1, s2);

For me the assignment h1=h2 means they are.the same. And so the output 
of the combinatorial function "twelve" is immediately fed back to its 
input


This here also looks extremely strange:
1
        if(reset)begin

2
            h1 <= 4'h2;

3
            h2 <= 4'h1;

4
        end else begin   

5
           if(four & reset)begin 

6
              h1 <= 4'h2;       // will never ever be reached... 

7
              h2 <= 4'h1;

8
           end else if(four & ~reset)

9
   ....
Reply Quote Edit Delete Report post
Watch this topic

Reply

Note: the original post is older than 6 months. Please don't ask any new questions in this thread, but start a new one.

Formatting
  • [c]C-Code[/c]
  • [vhdl]VHDL-Code[/vhdl]
  • [code]code in other languages, ASCII drawings[/code]
  • [math]formula (LaTeX syntax)[/math]
  • [[Title]] – link to an article
  • Link to another post: right-click its post ID (#8078628), copy the address, paste it into the text

More about formatting

Post long source code as an attachment, not in the text.

Your name and e-mail address

Already registered? Log in

Not shown to anyone. We send you a link; your post appears once you confirm it there.

By submitting you create a free account and accept the terms of use.