The x86 architecture has a long and convoluted history dating back to 1978, when Intel announced the 16-bit 8086 microprocessor. IBM selected the 8086 and its cousin, the 8088, for IBM’s first personal computers. In 1985, Intel introduced the 32-bit 80386 microprocessor, which was backward ...
The 8086 microprocessor provided eight 16-bit registers. It could separately access the upper and lower eight bits of some of these registers. When the 32-bit 80386 was introduced, the registers were extended to 32 bits. These registers are called EAX, ECX, EDX, EBX, ESP, EBP, ESI, and...
The x86mf instruction instructs processor 104 to move a value in a specified x86 integer register to a specified 64 bit integer register. Processor 104 then performs operations using the value in the 64 bit integer register. When processor 104 decodes and executes move to instruction 214, proce...
The String Instruction in 8086 are namely, REP is a prefix which is written before one of the string instructions. These instructions repeat
The Processor, upon encountering in its instruction stream an instruction having a particular Operation word format, will transfer a Command word following the Operation word to a particular Coprocessor designated by a Coprocessor Identity field in the Operation word. Upon decoding the Command word, ...
instructionsetarchitecture
Although the 8080 was widely used in embedded systems, it is more famous for its use in the first generation of home computers, boxes such as the Altair and IMSAI. Famed chip designer Federico Faggin said that the 8080 really created the microprocessor; the 4004 and 8008 suggested it, but ...
A simplified method and apparatus for handling the change of instruction control flow in a microprocessor is provided. Rather than attempting to implement a change in the instruction flow immediately,
An instruction scanning unit for a superscalar microprocessor is disclosed. The instruction scanning unit processes start and end byte information associated with a plurality of contiguous instruction bytes. The processing of start byte information and end byte information is performed independently and in...
2. A condition code generating means as set forth in claim 1 wherein said means for converting the hexadecimal result back into a BCD format include means for subtracting the decimal value 6 from those BCD digits where a corresponding bit in the conditions register (CA, C4, C8, . . . CN...