MPC_I2C_FDR
readb(i2c->base + MPC_I2C_FDR));
writeb(fdr & 0xff, i2c->base + MPC_I2C_FDR);
readb(i2c->base + MPC_I2C_FDR));
writeb(fdr & 0xff, i2c->base + MPC_I2C_FDR);
i2c->fdr = readb(i2c->base + MPC_I2C_FDR);
writeb(i2c->fdr, i2c->base + MPC_I2C_FDR);