14 svts - save task register and descriptor – AMD Geode LX [email protected] User Manual
Page 657
AMD Geode™ LX Processors Data Book
657
Instruction Set
33234H
Exceptions
#UD
If current privilege level is not 0, or the SMM_INST_EN = 0 and if the processor is not in SMM and if the processor
is not in DMM.
Notes
The reg field within the mod r/m byte must be zero for the SVLDT instruction to be recognized.
8.3.4.14 SVTS - Save Task Register and Descriptor
Operation
Description
Write the Task register and descriptor to memory. Below is the format of the descriptor contents in memory..
Flags Affected
None.
Exceptions
#UD
If current privilege level is not 0, or the SMM_INST_EN = 0 and if the processor is not in SMM and if the processor
is not in DMM.
Notes
The reg field within the mod r/m byte must be zero for the SVTS instruction to be recognized.
Opcode
Instruction
Clocks
Description
0F 7C
SVTS m80
8
Save TS to memory
31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 15 14 13 12 11 10
9
8
7
6
5
4
3
2
1
0
SELECTOR[15:3]
TI
RPL
+8
BASE[31:24]
G
B
0
V
LIMIT[19:16]
1
DPL
1
0
E
W
A
BASE[23:16]
+4
BASE[15:0]
LIMIT[15:0]
+0
IF (CPL<>0 OR (SMM_INST_EN=0 AND SMM=0 AND DMM=0))
#UD;
ELSE
MEM80 <= TS.DESCR;