Intel 64 and IA-32 Architectures Software Developers Manual Volume 2B, Instruction Set Reference, N-Z

Vol. 2B 4-247
INSTRUCTION SET REFERENCE, N-Z
RDX[31:0] ← TimeStampCounter[63:32];
RDX[63:32] ← 0;
ELSE
EDX:EAX ← TimeStampCounter;
FI;
ELSE (* CR4.TSD = 1 and (CPL = 1, 2, or 3) and CR0.PE = 1 *)
#GP(0);
FI;
Flags Affected
None.
Protected Mode Exceptions
#GP(0) If the TSD flag in register CR4 is set and the CPL is greater than
0.
Real-Address Mode Exceptions
None.
Virtual-8086 Mode Exceptions
#GP(0) If the TSD flag in register CR4 is set.
Compatibility Mode Exceptions
Same exceptions as in Protected Mode.
64-Bit Mode Exceptions
Same exceptions as in Protected Mode.