Define some Important Point for bit fields with structures?

• Only n lower bits will be assigned to an n bit number thus type cannot take values larger than 15 (4 bits long)
• Bit fields are forever converted to integer type for computation.
• You are permitted to mix ``normal'' types with bit fields.
• The unsigned definition is important-ensures that no bits are used as a flag.

Fig. Example Disk Controller Register

Often device controllers (e.g. disk drives) and the operating system require communicating at a low level and the device controllers contain several registers which may be packed together in one integer (See Figure).