I2C_IBSR
if ((READ1(sc, I2C_IBSR) & IBSR_IBB) == 0)
ibsr = READ1(sc, I2C_IBSR);
WRITE1(sc, I2C_IBSR, IBSR_IBIF);
WRITE1(sc, I2C_IBSR, IBSR_IBAL);
return (READ1(sc, I2C_IBSR) & IBSR_RXAK) ? false : true;
if ((READ1(sc, I2C_IBSR) & IBSR_IBB) == 0) {
WRITE1(sc, I2C_IBSR, IBSR_IBIF);