MPC_I2C_DFSRR
readb(i2c->base + MPC_I2C_DFSRR),
writeb((fdr >> 8) & 0xff, i2c->base + MPC_I2C_DFSRR);
i2c->dfsrr = readb(i2c->base + MPC_I2C_DFSRR);
writeb(i2c->dfsrr, i2c->base + MPC_I2C_DFSRR);