What is the CPU control register?

Control register is called a processor register that changes or controls the general behaviour of a CPU or other services in the system.

The common tasks performed by control registers are interrupt control, switching the addressing mode, paging control, and coprocessor control.

Types of CPU Control Register

The different types of CPU control register are as follows −

The control registers are those extra registers that are visible only in kernel mode.

  • CR0 - Reads as 0, read-only
  • CR1 - For general-purpose use
  • CR2 - For general-purpose use
  • CR3 - For general-purpose use and TLB interface
  • CR4 - Processor Status Register
  • CR5 - Interrupt Status Register
  • CR6 - Interrupt Mask Register
  • CR7 - EPC Register

The bit definitions of control register as shown in diagram below −