MSR(Model-Specific Register) Additional, indirectly-accessible, registers containing control or status information about various aspects of the processor such as caches, performance counters, and the like. These registers, accessible via the RDMSR and WRMSR instructions, were added with the Pentium and later-model 486 processors. 00000259h - Pentium Pro - "MTRRfix16K_A0000"
Desc: control the 16K region from A0000h to A3FFFh