Please Help! Not gate implementation nand

Mihai M. OP #4445809
Rate this post
• ▲ useful
▼ not useful 
Hello everybody! I need some help. I use VHDL language and ModelSim PE 
Student Edition. I nade to build some elementary gates: not, or, xor, 
and, mux mux, dmux, 16 bit variants not16 and16 and multiway variants 
mux8way16 etc from nand gates. I made some schematics on paper and 
logic. Ex. Not imp. Nand : (a Nand b) Nand (a Nand b).
My first gate i want to buils is Not gate. (a nand a), for this i make 
this code:
1
library IEEE;

2
use ieee.std_logic_1164.all;

3


4
entity noot is

5
         port (a : in std_logic;

6
               cout : out std_logic

7
              );

8
end noot;

9


10
architecture behavior of noot is

11
          component naand

12
           port(

13
                a1 : in std_logic;

14
                b1 : in std_logic;

15
               );

16
          end component;

17


18
     NA1 : naand port map (

19
                a1 =>a,

20
                b1 =>a,

21
                out1 => cout

22
                );

so here is my problem, how i can do the function of nand?
it was simple to write:
1
 

2
 cout<= a nand a;

but i want later to add more nand gates in separate bloks
i try with signal
1
signal s1, s2 : std_logic := '0'; or without ":= '0'"

2
 NA1 : naand port map (

3
                a1 =>s1,

4
                b1 =>s2,

5
                out1 => cout => s1 nand s2

6
                );

How i can make this to work?

This is schematic of wat i want:
1
           

2
                        NOT GATE

3
            ____________________________      

4
           |            ________        |     

5
           |      _____|        \       |

6
    a      |     /     |         \      |  cout

7
-----------|----=      |   NAND   |-----|-------

8
           |     \_____|         /      |

9
           |           |________/       |

10
           |____________________________|
Reply Quote Edit Move Thread sperren Anmeldepflicht aktivieren Anpinnen Delete topic Thread mit anderem zusammenführen Report post
Lothar M. Moderator (Company: Titel) #4445934
Rate this post
• ▲ useful
▼ not useful 
Mihai M. wrote:
> I use VHDL language
Pls have a look at the screenshot...

> component naand
That component has no output. Its useless and will be optimized away.

> out1 => cout => s1 nand s2
What should this do?
In a port map you ca assign 1 port to 1 signal.
> How i can make this to work?

> This is schematic of wat i want
I'm not able to figure out your problem... :-/

> so here is my problem, how i can do the function of nand?
Try it this way and think about it...
1
library IEEE;

2
use ieee.std_logic_1164.all;

3


4
entity naand is

5
         port (a1,b1 : in std_logic;

6
               out1 : out std_logic);

7
end noot;

8


9
architecture behavior of naand is

10
begin

11
    out1 <= a1 nand b1;

12
end behavior;

13


14


15


16
library IEEE;

17
use ieee.std_logic_1164.all;

18


19
entity noot is

20
         port (a : in std_logic;

21
               cout : out std_logic

22
              );

23
end noot;

24


25
architecture behavior of noot is

26
     component naand

27
         port (a1,b1 : in std_logic;

28
               out1 : out std_logic);

29
     end component;

30


31
     NA1 : naand port map (

32
                a1 => a,

33
                b1 => a,

34
                out1 => cout

35
                );

36
end behavior;
Attached files:
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.