ex-basics-enum.v

// Declare enum type

typedef enum logic [$clog2(4)-1:0] {
  STATE_A,
  STATE_B,
  STATE_C,
  STATE_D
} state_t;

module top;

  // Declare variables

  state_t state;
  logic   result;

  initial begin

    // Enum lable literals

    state = STATE_A; $display( "STATE_A = %d", state );
    state = STATE_B; $display( "STATE_B = %d", state );
    state = STATE_C; $display( "STATE_C = %d", state );
    state = STATE_D; $display( "STATE_D = %d", state );

    // Comparisons

    state = STATE_A;

    result = ( state == STATE_A );
    $display( "( STATE_A == STATE_A ) = %x", result );

    result = ( state == STATE_B );
    $display( "( STATE_A == STATE_B ) = %x", result );

    result = ( state != STATE_A );
    $display( "( STATE_A != STATE_A ) = %x", result );

    result = ( state != STATE_B );
    $display( "( STATE_A != STATE_B ) = %x", result );

  end

endmodule