Intel 253668-032US User Manual

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6-42   Vol. 3
INTERRUPT AND EXCEPTION HANDLING
Interrupt 10—Invalid TSS Exception (#TS)
Exception Class
Fault.
Description
Indicates that there was an error related to a TSS. Such an error might be detected 
during a task switch or during the execution of instructions that use information from 
a TSS. Table 6-6 shows the conditions that cause an invalid TSS exception to be 
generated. 
Table 6-6.  Invalid TSS Conditions  
Error Code Index
Invalid Condition
TSS segment selector index The TSS segment limit is less than 67H for 32-bit TSS or less than 
2CH for 16-bit TSS.
TSS segment selector index During an IRET task switch, the TI flag in the TSS segment selector 
indicates the LDT.
TSS segment selector index During an IRET task switch, the TSS segment selector exceeds 
descriptor table limit.
TSS segment selector index During an IRET task switch, the busy flag in the TSS descriptor 
indicates an inactive task.
TSS segment selector index During an IRET task switch, an attempt to load the backlink limit 
faults.
TSS segment selector index During an IRET task switch, the backlink is a NULL selector.
TSS segment selector index During an IRET task switch, the backlink points to a descriptor 
which is not a busy TSS.
TSS segment selector index The new TSS descriptor is beyond the GDT limit.
TSS segment selector index The new TSS descriptor is not writable.
TSS segment selector index Stores to the old TSS encounter a fault condition.
TSS segment selector index The old TSS descriptor is not writable for a jump or IRET task 
switch.
TSS segment selector index The new TSS backlink is not writable for a call or exception task 
switch.
TSS segment selector index The new TSS selector is null on an attempt to lock the new TSS.
TSS segment selector index The new TSS selector has the TI bit set on an attempt to lock the 
new TSS.
TSS segment selector index The new TSS descriptor is not an available TSS descriptor on an 
attempt to lock the new TSS.
LDT segment selector index LDT or LDT not present.