A general protection fault (GPF) in the Intel x86 and AMD x86-64 types of computer microprocessor architectures, and other unrelated architectures, is a fault (a type of interrupt) that can encompass several cases in which protection mechanisms within the processor architecture are violated by any of the programs that are running, either the kernel or a user program. The mechanism is first described in section 9.8.13 in the Intel 80386 programmer's reference manual from 1986. A general protection fault is implemented as an interrupt (vector number 13 in decimal) in both the x86 and the AMD64 architectures.