Search results
Results from the WOW.Com Content Network
IA-64 (Intel Itanium architecture) is the instruction set architecture (ISA) of the discontinued Itanium family of 64-bit Intel microprocessors. The basic ISA specification originated at Hewlett-Packard (HP), and was subsequently implemented by Intel in collaboration with HP. The first Itanium processor, codenamed Merced, was released in 2001.
The Intel Model-Specific Registers (MSRs) are described in-depth in the Intel® 64 and IA-32 Architectures Software Developer’s Manual, Volume 4; the link to the Intel reference manuals (PDFs) download page (which includes Vol 4):
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 memory addresses of the handlers to be executed on interrupts and exceptions. The details in the description below apply specifically to the x86 architecture.
Intel's second generation of 32-bit x86 processors, introduced built-in floating point unit (FPU), 8 KB on-chip L1 cache, and pipelining. Faster per MHz than the 386. Small number of new instructions. P5 original Pentium microprocessors, first x86 processor with super-scalar architecture and branch prediction. P6
Memory-mapped I/O is preferred in IA-32 and x86-64 based architectures because the instructions that perform port-based I/O are limited to one register: EAX, AX, and AL are the only registers that data can be moved into or out of, and either a byte-sized immediate value in the instruction or a value in register DX determines which port is the source or destination port of the transfer.
Below is the full 8086/8088 instruction set of Intel (81 instructions total). [2] These instructions are also available in 32-bit mode, in which they operate on 32-bit registers (eax, ebx, etc.) and values instead of their 16-bit (ax, bx, etc.) counterparts.
SSSE3 contains 16 new discrete instructions. Each instruction can act on 64-bit MMX or 128-bit XMM registers. Therefore, Intel's materials refer to 32 new instructions. They include: [1] Twelve instructions that perform horizontal addition or subtraction operations. Six instructions that evaluate absolute values.
The x86-64 architecture does not use segmentation in long mode (64-bit mode). Four of the segment registers, CS, SS, DS, and ES, are forced to base address 0, and the limit to 2 64. The segment registers FS and GS can still have a nonzero base address. This allows operating systems to use these segments for special purposes.