3-197
INSTRUCTION SET REFERENCE
FFREEFree Floating-Point Register
Description
This instruction sets the tag in the FPU tag register associated with register ST(i) to empty (11B).
The contents of ST(i) and the FPU stack-top pointer (TOP) are not affected.
Operation
TAG(i)
<
11B;
FPU Flags Affected
C0, C1, C2, C3 undefined.
Floating-Point Exceptions
None.
Protected Mode Exceptions
#NM
EM or TS in CR0 is set.
Real-Address Mode Exceptions
#NM
EM or TS in CR0 is set.
Virtual-8086 Mode Exceptions
#NM
EM or TS in CR0 is set.
Opcode
Instruction
Description
DD C0+i
FFREE ST(i)
Sets tag for ST(i) to empty
