IIC_ICR_TB
sc->sc_icr | IIC_ICR_START | IIC_ICR_TB);
sc->sc_icr | IIC_ICR_TB | (last_byte ? IIC_ICR_NACK : 0) |
sc->sc_icr | IIC_ICR_TB | (send_stop ? IIC_ICR_STOP : 0));