Register Diagram

The following diagram summarizes the fields and functions of the control registers in the Pentium™ Pro microprocessor. The registers are commonly designated CR4 through CR0 (CR4:0), although CR1 is not actually implemented. They are used by the operating system to specify and monitor basic functions of processor behavior.

The diagram is designed for an audience of system-software programmers who have experience with x86 (Intel-compatible) operating systems. Such programmers can get most of the information they need from this compact diagram, without having to read the accompanying details.