Search Results for: Direct Memory Access

Virtual 8086 Mode in Microprocessor: The virtual 8086 mode is a special operating mode of the Pentium processor and it is a subset of protected mode. In this mode, two 8086 application programs can be executed at the same time. During virtual 8086 mode operation, the segment registers are used in the similar way as […]

Linear, Logical Address and Physical Address in Microprocessor: The Linear, Logical Address and Physical Address in Microprocessor is given below Physical Address In protected mode, the Intel Architecture (IA) 32-bit processors/Pentium processors provide a usual physical address space of 232 bytes or 4 Gbytes. Therefore, the processor can address up to 4 Gbytes memory locations

Operating Modes of Pentium Processor: The Pentium processor architecture supports three Operating Modes of Pentium Processor such as protected mode, real-address mode and System Management Mode (SMM) and one ‘quasi-operating mode’ or virtual-8086 mode. In this section, all Operating Modes of Pentium Processor are explained in detail. Protected Mode The protected mode is the local

Features of 80186, 80286, 80386 and 80486 Microprocessor: Let us discuss the Features of 80186 Microprocessor, Features of 80286 Microprocessor, Features of 80386 Microprocessor, Features of 80486 Microprocessor one by one Features of 80186 Microprocessor: In 1982, the 80186 microprocessor was developed by Intel. This is an improved 8086 with several common functions built in blocks

Pin Diagram of 80486 Microprocessor: The pin diagram of 168-pin PGA (Pin Grid Array) package 80486 is shown in Fig. 11.49 and the schematic Pin Diagram of 80486 Microprocessor is depicted in Fig. 11.50. All signals of 80486 are grouped according to their functions. Some of the most important groups of signals are explained in

Operating Modes of 80386 Microprocessor: The Operating Modes of 80386 Microprocessor are given below: Real addressing mode, Protected mode, and Virtual 386 mode. In this section, the above three modes are explained elaborately. Real addressing mode The 80386 always starts from the memory location FFFFFFF0H in the real address mode whenever the pro­cessor is reset.

Registers of 80386 Microprocessor: The 80386 processor has significantly extended the 8086 register set. All the registers of 80286 are existing in the 80386 processor and some new registers have been added in 80386. Generally, the registers of 80386 microprocessor are of 32 bits and they can be used as 8-bit and 16-bit registers. Figure

Protected Virtual Address Mode (PVAM) in 80286: Protected Virtual Address Mode (PVAM) in 80286 – The 80286 executes a fully upward-compatible superset of the 8086 instruction set in protected virtual address mode. The PVAM operation of the 80286 processor provides memory management and protection mechanisms and associated instructions. The 80286 enters into protected virtual address

80286 Instruction Set: The 80286 Instruction Set are upwardly compatible with that of the 8086 processor. Most of the 80286 Instruction Set are the same as the instructions of 8086. The additional instructions of 80286 processor are as follows: ARPL (Adjust RPL Field of Segment Selector) CLTS (Clear Task Switched Flag in CRO) LAR (

Addressing Modes of 80286 Microprocessor: The 80286 has eight addressing modes for instructions to access operands from memory. The eight different Addressing Modes of 80286 Microprocessor are as follows: Register operand mode Immediate operand Direct mode Register indirect mode Based mode Indexed mode Based indexed mode Based indexed mode with displacement The first two operating