Important Note: This simulation is optimized for desktop view. For the best experience, please use a desktop monitor with a minimum resolution of 1280x720 pixels. Mobile devices and tablets are not supported.

Implementation Steps

1. Module Setup

1. Select Adder Type

   • Choose between Half Adder or Full Adder using the tabs
   • Each type has specific port requirements:
     • Half Adder: 2 inputs, 2 outputs
     • Full Adder: 3 inputs, 2 outputs

2. Naming Conventions

   • Module Name Rules:
     • Start with a letter
     • Use only letters, numbers, and underscores
     • No special characters or spaces
     • Example: half_adder, full_adder
   • Testbench Name Rules:
     • Must end with '_tb'
     • Example: half_adder_tb, full_adder_tb

2. Module Implementation

Half Adder Implementation Steps

1. Port Declaration

   module half_adder(
                 input A,
                 input B,
                 output Sum,
                 output Carry
             );
             

2. Logic Implementation

   assign Sum = A ^ B;      // XOR operation
             assign Carry = A & B;    // AND operation
             

Full Adder Implementation Steps

1. Port Declaration

   module full_adder(
                 input A,
                 input B,
                 input Cin,
                 output Sum,
                 output Carry
             );
             

2. Logic Implementation

   wire sum1;              // Intermediate sum
             wire carry1, carry2;    // Intermediate carries
             
             // First half adder
             assign sum1 = A ^ B;
             assign carry1 = A & B;
             
             // Second half adder
             assign Sum = sum1 ^ Cin;
             assign carry2 = sum1 & Cin;
             
             // Final carry
             assign Carry = carry1 | carry2;
             

3. Testbench Creation

1. Signal Declaration

   • Half Adder:

     reg A, B;
               wire Sum, Carry;
               

   • Full Adder:

     reg A, B, Cin;
               wire Sum, Carry;
               

2. Module Instantiation

   • Half Adder:

     half_adder ha(
                   .A(A),
                   .B(B),
                   .Sum(Sum),
                   .Carry(Carry)
               );
               

   • Full Adder:

     full_adder fa(
                   .A(A),
                   .B(B),
                   .Cin(Cin),
                   .Sum(Sum),
                   .Carry(Carry)
               );
               

3. Test Cases

   • Half Adder: Test all 4 combinations (00, 01, 10, 11)
   • Full Adder: Test all 8 combinations (000 to 111)

4. Validation Process

1. Code Validation

   • Click "Validate" to check:
     • Syntax correctness
     • Port connections
     • Logic implementation
     • Testbench coverage

2. Expected Results

   • Successful validation shows:
     • Truth table with all input combinations
     • Waveform visualization
     • Timing analysis

5. Common Implementation Errors

1. Syntax Errors

   • Missing semicolons
   • Incorrect port declarations
   • Improper module structure

2. Logic Errors

   • Incorrect operator usage
   • Missing intermediate signals
   • Wrong port connections

3. Testbench Errors

   • Incomplete test cases
   • Wrong signal declarations
   • Incorrect port mapping

6. Best Practices

1. Code Organization

   • Use consistent indentation
   • Add meaningful comments
   • Follow naming conventions

2. Testing Strategy

   • Test all input combinations
   • Verify edge cases
   • Check timing constraints

3. Documentation

   • Document module interfaces
   • Explain complex logic
   • Include test scenarios

Note: This guide focuses on practical implementation steps. For theoretical concepts and detailed explanations, refer to the theory.md file.