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Intel Pentium CPU Instruction Set Reference

CLI instruction - Clear Interrupt Flag

Code Mnemonic Description
FA CLI Clear interrupt flag; interrupts disabled when interrupt flag cleared


Clears the IF flag in the EFLAGS register. No other flags are affected. Clearing the IF flag causes the processor to ignore maskable external interrupts. The IF flag and the CLI and STI instruction have no affect on the generation of exceptions and NMI interrupts.

Operands Bytes Clocks
  1 7 NP


ID unaffected DF unaffected
VIP unaffected IF cleared to 0 if the CPL is equal to or less than the IOPL; otherwise, it is not affected
VIF unaffected TF unaffected
AC unaffected SF unaffected
VM unaffected ZF unaffected
RF unaffected AF unaffected
NT unaffected PF unaffected
IOPL unaffected CF unaffected
OF unaffected