registers.) This instruction can be executed only when the current privilege level is 0.</p>
<p>At the opcode level, the <em>reg</em> field within the ModR/M byte specifies which of the control registers is loaded or read. The 2 bits in the <em>mod </em>field are ignored. The <em>r/m</em> field specifies the general-purpose register loaded or read. Attempts to reference CR1, CR5, CR6, CR7, and CR9–CR15 result in undefined opcode (#UD) exceptions.</p>
<p>When loading control registers, programs should not 