Verilog input error

Question

I have a couple of errors in my verilog code that pop up when I compile. I believe they are all related. But I can't figure out what the error is. Any help will be greatly appreciated.

The errors are: Two for the input

vlog_a: Error 31004 Syntax error near `input' found

blog_a: Error 31004 Syntax error near 'output' found

module threeBitComparator; 
  input A2,A1,A0;
  input B2,B1,B0;
  output E,GE; //E-Equal,  GE-Greater than or Equal to

  wire X1,X2,X3; //xnor gate
  wire Y1,Y2,Y3,Y4,Y5,Y6; // and & or gates

  xnor
      G1a(X1,A2,B2),
      G1b(X2,A1,B1),
      G1c(X3,A0,B0);

  and
     G2a(Y1,A2,~B2),
     G2b(Y2,A1,~B1),
     G2c(Y3,A0,~B0),
     G2d(Y4,X1,Y2),
     G2e(Y5,X1,X2,Y3),
     G2f(E,X1,X2,X3);

  or
    G3a(Y6,Y1,Y4,Y5),
    G3b(GE,Y6,E);
endmodule

Greg · Accepted Answer · 2017-06-06 14:55:11Z

1

You declared your inputs and outputs but you haven't declared a port list. Your module header needs to look like below code to be IEEE 1364-1995 complaint

module threeBitComparator(A2,A1,A0,B2,B1,B0,E,GE); // <-- port list
  input A2,A1,A0;
  input B2,B1,B0;
  output E,GE; //E-Equal,  GE-Greater than or Equal to

Or you can use the ANSI style header introduce in IEEE Std 1364-2001. This style works on any modern Verilog simulator.

module threeBitComparator(
  input A2,A1,A0,
  input B2,B1,B0,
  output E,GE ); //E-Equal,  GE-Greater than or Equal to

answered Jun 6, 2017 at 14:55

Greg

19.3k6 gold badges51 silver badges72 bronze badges

Sign up to request clarification or add additional context in comments.

Comments

Rahul Behl · Accepted Answer · 2017-06-06 05:03:41Z

0

I think you forgot to declare your input and output in the module port lists. Adding A2, A1..., etc to the port list will solve the compilation errors.

You can check the updated code here.

answered Jun 6, 2017 at 5:03

Rahul Behl

3911 silver badge11 bronze badges

Collectives™ on Stack Overflow

Verilog input error

2 Answers 2

Comments

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

Comments

Comments

Your Answer

Sign up or log in

Post as a guest

Related