Hlt

Please note that the content of this book primarily consists of articles available from Wikipedia or other free sources online. In the x86 computer architecture, HLT (halt) is an assembly language instruction which halts the CPU until the next external interrupt is fired. Most of the commonly used devices use interrupts for their interaction with drivers. The HLT instruction is run when an operating system enters its idle loop and there is no immediate work to be done. In Windows NT for example, this instruction is run in the 'System Idle Process'.