In an example embodiment, a method writes individual bits of data to a register. Bits of data are received in a data field. The number of bits in the data field is equal to the number of bits in the register and the bit locations in the data field correspond respectively to the bit locations in the register. Enable bits are received in a bit enable field. The number of enable bits in the bit enable field is equal to the number of bits in the register. The bit locations in the bit enable field correspond respectively to bit locations in the register. Only the bits at the bit locations of the register for which the enable bit in the corresponding location in the bit enable field is set are overwritten with the bit in the corresponding location in the data field.