<'
struct instruction { 
    %opcode     : uint (bits : 3); 
    %operand    : uint (bits : 5); 
    %address    : uint (bits : 8); 
    !data_packed_high : list of bit; 
    !data_packed_low  : list of bit; 
    keep opcode ==  0b100; 
    keep operand == 0b11001; 
    keep address == 0b00001111; 
    post_generate() is also {
       data_packed_low = pack(packing.low, opcode, operand); 
       data_packed_high = pack(packing.high, opcode, operand);  
    };
};

extend sys {
  ins : instruction;
  run() is also {
    print ins using bin;
    print ins.data_packed_low using bin;
    print ins.data_packed_high using bin;
  };
};
'>