I2C_INTERRUPT_MASK_REGISTER
WR4(sc, I2C_INTERRUPT_MASK_REGISTER, 0);
reg = RD4(sc, I2C_INTERRUPT_MASK_REGISTER);
WR4(sc, I2C_INTERRUPT_MASK_REGISTER, 0);
reg = RD4(sc, I2C_INTERRUPT_MASK_REGISTER);
WR4(sc, I2C_INTERRUPT_MASK_REGISTER, reg);
reg = RD4(sc, I2C_INTERRUPT_MASK_REGISTER);
WR4(sc, I2C_INTERRUPT_MASK_REGISTER, reg);
reg = RD4(sc, I2C_INTERRUPT_MASK_REGISTER);
WR4(sc, I2C_INTERRUPT_MASK_REGISTER, reg);
WR4(sc, I2C_INTERRUPT_MASK_REGISTER, 0);
WR4(sc, I2C_INTERRUPT_MASK_REGISTER, mask);
WR4(sc, I2C_INTERRUPT_MASK_REGISTER, 0);