IBCR_IBIE
reg |= (IBCR_RSTA | IBCR_IBIE);
reg = (IBCR_MSSL | IBCR_NOACK | IBCR_IBIE | IBCR_TXRX);
WRITE1(sc, I2C_IBCR, IBCR_NOACK | IBCR_IBIE);
WRITE1(sc, I2C_IBCR, IBCR_IBIE | IBCR_MSSL | IBCR_NOACK);
WRITE1(sc, I2C_IBCR, IBCR_IBIE | IBCR_MSSL);
WRITE1(sc, I2C_IBCR, IBCR_IBIE | IBCR_MSSL | IBCR_NOACK);
WRITE1(sc, I2C_IBCR, IBCR_IBIE | IBCR_NOACK);