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Introduction of Intel Processors. Intel 4004 (First Microprocessor) : 1969. First Microprocessor Revolution from fixed functionality to variable Handled 4 bit data Had 46 instructions Allowed 4KB of program code and 1KB of data. Intel 8-bit processors. They are 8008, 8080 and 8085
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Intel 4004 (First Microprocessor) : 1969 • First Microprocessor • Revolution from fixed functionality to variable • Handled 4 bit data • Had 46 instructions • Allowed 4KB of program code and 1KB of data.
Intel 8-bit processors • They are 8008, 8080 and 8085 • They were used • in many early microcomputers • in applications such as electronic instruments and printers
Intel 16-bit processors • They included 8086, 8088 and 80286
Intel 32-bit processors • They include 80386 and 80486. • First they introduced 80386DX, 80386SX and 80386SL. • It was compatible with 8088/8086/80286 • 80386DX(DX refers to floating point capability) • 80386SX(SX refers to 16-bit data bus) • It offers 24 bit address bus(16MB physical m/m) • 80386SL(offered several power management options and sleep modes to conserve battery power for laptops)
Intel 32-bit processor - 80486 • 80486DX – Improved with memory cache and math coprocessor • 80486SX – Does not have math coprocessor • Clock doubler/tribler were also released (75% faster than the comparable non-doubled processor) • DX2-66 33MHz • DX2-50 25MHz • DX4-100 25MHz • DX4-75 25MHz
Features of 80386DX • It supports 8/16/32 bit data operands • It has 32-bit internal registers • It supports 32-bit data bus and 32-bit non-multiplexed address bus • It supports • Physical Address of 4GB • Virtual Address of 64TB • Maximum Segment size of 4GB
Features of 80386DX • It operates in 3 different modes • Real • Protected • Virtual 8086 • MMU provides virtual memory, paging and 4 levels of protection • Clock Frequency : 20,25 and 33MHz • It has 132 pin package
Architecture of 80386 UQ: Draw the block diagram of the 80386 DX Processor and explain each block in brief
Architecture of 80386 • Three Sections: • Bus Interface units • Central Processing Unit • Memory Management Unit
Architecture of 80386 • The internal architecture of 80386 is divided into three sections: • Central Processing Unit • Memory Management Unit • Bus Interface unit
Central Processing Unit • The CPU is further divided into: • Instruction Unit • Execution Unit • Instruction Unit: • It decodes the opcode bytes received from the 16-byte instruction queue and arranges them into a 3-decoded instruction queue. • After decoding it is passed to control section for deriving necessary control signals
Central Processing Unit • Execution Unit: • It has 8 general purpose and 8 special purpose registers which either handles data or addresses • The 64-bit barrel shifter increases the speed of all shift, rotate, multiply and divide operations • The multiply/divide logic implements the bit-shift-rotate algorithms to complete the operations in minimum time(Even 32bit multiplication is done in 1µs)
Central Processing Unit • Element of the EU • Arithmetic/logic unit (ALU) • Performs the operation identified by ADD, SUB, AND, etc. • Flags register • Holds status and control information • General-purpose registers • Holds address or data information • Control ROM • Contains microcode sequences that define operations performed by machine instructions • Special multiply, shift, and barrel shift hardware • Accelerate multiply, divide, and rotate operations
Memory Management Unit • MMU consists of a segmentation unit and paging unit • Segmentation Unit: • It allows the use of two address components - segment and offset – for relocability and sharing of data • It allows a maximum segment size of 4GB • It provides a 4-level protection mechanism for protecting and isolating system’s code and data from those of application program
Memory Management Unit • The limit and attribute PLA checks segment limits and attributes at segment level to avoid invalid accesses to code and data in memory segment. • Paging Unit • It organizes physical memory in terms of pages of 4KB size • It works under the control of segmentation unit • It converts linear addresses into physical addresses • The control and attribute PLA checks privileges at page level.
Bus Interface Unit • It has a prioritizer to resolve the priority of various bus requests. This controls the access of the bus • The address driver drives the bus enable and address signals A2 – A31. • The pipeline/bus size unit handles the control signals for pipelining and dynamic bus sizing units
Bus Interface Unit • The data buffers interface the internal data bus with system bus