Hello,

I am trying to design a memory element using VerilogA. In the case where the voltage goes between +Vtmax and -Vtmax, the code doesnt remember the previous value of x and the control directly jumps to else statement. How can I make it remember the previous value of x? Below is a piece of my code:

 analog
   begin
         `INITIAL_MODEL

       begin

x=0;
end

x = V(state);

if (V(G,S) >= Vtmax) begin      
                 R=Rp;
                 V(D) <+ I(D)* Rp;
                 x= 0;
                       end

else if (V(G,S) <= -Vtmax)  begin      
                 R=Rap;
                 V(D) <+ I(D)* Rap;
                 x= 1;                  
                 end
else if ( -Vtmax < V(G,S) < Vtmax)
                 begin
                       if(x==0) begin
                             R=Rap;
                             V(D) <+ I(D)* Rap;
                             x= 1;
                             
                             end
                       else if (x==1) begin
                             R=Rp;
                             V(D) <+ I(D)* Rp;
                             x= 0;
                             
                             end
                       else                        
                       V(D) <+ 0;
                 end
else   V(D) <+ 0;                    
V(state)<+ x;
end
endmodule  

Please help me on this.

This isn't legal Verilog-A:
Quote:

Nishtha,
   If you want people to help you you should try to make it easy for them to do so. Posting a large, poorly formatted block of code that has no comments or explanation and is incomplete makes it very difficult to help. Kudos to Geoffrey for at least trying. I stared at your post for about 15 minutes and gave up.

When asking questions about code you should:
1. Try to boil down your code so that it is as small and simple as possible to make it easy to others to understand it.
2. Use the # (code) tag so that formatting is retained.
3. Properly format you code.
4. Send the complete model so that someone could copy and paste into a file and try it if need by. When you leave stuff out, you may just leave out the real problem. Remember, you don't understand what is going on, that is why you are asking questions, and so you may not have the best judgment of what can be safely left out.
5. Explain your code.

If you do all that, you just might find that you can answer your question yourself. If not, you are much more likely to get a helpful response.

-Ken

Hello,

I followed your guidance line by line and I was able to solve the issue. My code works fine now. Thanks a lot!

Best,
Nishtha
Ken Kundert wrote on Feb 16^th, 2016, 2:05pm:

Nishtha wrote on Feb 16^th, 2016, 9:06pm:


Could you please post the updated code and also point out where the error was at?