SUBDESIGN 'lab4'
(
  a, b, clock: INPUT;
  out[3..0]: OUTPUT;
)
VARIABLE
  state: MACHINE WITH STATES (s0, s1, s2, s3, s4, s5, s6, s7, s8, s9, s10, s11, s12, s13, s14, s15);

BEGIN
  state.clk = clock;
  case state is
    when s0 =>
      out[] = B"0011";
      state = s1;
    when s1 =>
      out[] = B"1011";
      if (a==1) then
        state = s2;
      else
        state = s8;
      END if;
    when s2 =>
      out[] = B"1100";
      state = s3;
    when s3 =>
      out[] = B"0001";
      if (b==1) then
        state = s5;
      else
        state = s4;
      END if;
    when s4 =>
      out[] = B"1001";
      state = s6;
    when s5 =>
      out[] = B"0010";
      state = s6;
    when s6 =>
      out[] = B"1110";
      state = s7;
    when s7 =>
      out[] = B"1000";
      state = s13;
    when s8 =>
      out[] = B"0111";
      state = s9;
    when s9 =>
      out[] = B"0110";
      state = s10;
    when s10 =>
      out[] = B"0100";
      if (b==1) then
        state = s11;
      else
        state = s12;
      END if;
    when s11 =>
      out[] = B"1101";
      state = s7;
    when s12 =>
      out[] = B"1010";
      state = s7;
    when s13 =>
      out[] = B"1111";
      state = s14;
    when s14 =>
      out[] = B"0101";
      state = s15;
    when s15 =>
      out[] = B"0000";
      state = s0;
    when others =>
      state = s0;
  END case;
END;