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The Interrupt Descriptor Table (IDT) is a data structure used by the x86 architecture to implement an interrupt vector table. The IDT is used by the processor to determine the correct response to interrupts and exceptions. The details in the description below apply specifically to the x86 architecture and the AMD64 architecture. Other architectures have similar data structures, but may behave differently. Use of the IDT is triggered by three types of events: hardware interrupts, software interrupts, and processor exceptions, which together are referred to as "interrupts". The IDT consists of 256 interrupt vectors–the first 32 (0-31 or 00-1F) of which are reserved for processor exceptions. == Real mode == In the 8086 processor, the IDT resides at a fixed location in memory from address 0x0000 to 0x03ff, and consists of 256 four-byte real mode pointers (256 × 4 = 1024 bytes of memory).A real mode pointer is defined as a 16-bit segment address and a 16-bit offset into that segment. A segment address is expanded internally by the processor to 20 bits thus limiting real mode interrupt handlers to the first 1 megabyte of addressable memory. The first 32 vectors are reserved for the processor's internal exceptions, and hardware interrupts may be mapped to any of the vectors by way of a programmable interrupt controller. In the 80286 and later, the size and locations of the IDT can be changed in the same way as it is done in protected mode, though it does not change the format of it. A commonly used x86 real mode interrupt is , the Video BIOS code to handle primitive screen drawing functions such as pixel drawing and changing the screen resolution. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「interrupt descriptor table」の詳細全文を読む スポンサード リンク
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