1. step: CtrB: XXXX X0XX
         CtrA: XXXX X0XX

2. step: CtrB: XXXX X1XX
         CtrA: XXXX X0XX

3. step: CtrB: XXXX X0XX
         CtrA: XXXX X1XX

4. step: CtrB: XXXX X1XX
         CtrA: XXXX X1XX