Not chip output pin issue

[freak]

Hi there


while iam constructing AND chip,am getting proper output only when iam giving value of out =out or else if iam giving something like out=x in Not chip .eval button in hardware simulator is in disabled mode.

example 1)working

Not (in=NANDab,out = out);

Nand (a=a, b=b, out=NANDab);


example 2)not working

Not (in=NANDab,out = x);

Nand (a=a, b=b, out=NANDab);

coud any one help me out in this

[cadet1620]

freak wrote

example 2)not working

Not (in=NANDab,out = x);
Nand (a=a, b=b, out=NANDab);

Look at the header of the And.hdl file:

CHIP And {
    IN  a, b;
    OUT out;

The OUT line names the output pin(s) for the part. In this case there is one output named "out".

"out=x" creates an internal wire named "x". Nowhere in this chip is there any connection to the output pin named "out".

The "out" pin is connected in you working code.

When the simulator's Eval button is permanently disabled, it is usually because one or more chip output s are not connected.

--Mark