SAB_CCR2
r = SAB_READ(sc, SAB_CCR2);
SAB_WRITE(sc, SAB_CCR2, r);
SAB_WRITE(sc, SAB_CCR2, SAB_CCR2_BDF | SAB_CCR2_SSEL | SAB_CCR2_TOE);
r = SAB_READ(sc, SAB_CCR2);
SAB_WRITE(sc, SAB_CCR2, r);