Download - 15977 Advanced Microprocessors-80286
80286,80386 and 80486
Advanced Microprocessors
Introduction80286 is an first advanced Processor with
Memory management unit and Protection abilities
24 bit address bus available which can address 16 Mbytes of Physical memory
It runs with 12.5Mhz clock frequency It is compatible with its predecessors like 8086
and 8088 processorsIt works in 2 operating modes like
Address mode &Virtual Address mode
Real Address mode: 80286 can address up to 1Mb of physical memory address like 8086
Virtual Address mode:it can address up to 16 Mb of physical memory address space and 1 Gb of virtual memory address space
In real address mode, the 80286 is object code compatible with 8086.
In protected virtual address mode, it is source code compatible with 8086
Architecture of 80286
Comparison between 8086 and 80286 8086 Intel 8086 was developed in
1978 It has almost 3000 different
instruction for programming Peripheral ICs are not available
on board Operating frequencies are
between 5 to 10MHz No memory management
capability 20 bit address line, which can
access 2^20=1MB memory 8086 operates in Real
addressing mode Slow performance compared
with 80286 . Push and pop instructions are
used to store in stack memory
80286 Intel 80286 was developed 1983 More instructions available
compared to 8086 Peripheral ICs are available on
Board Operating frequencies are
between 8 to 12.5MHz 80286 has memory
management capability that maps 2^30 (1GB) virtual memory
Operates in Real mode and protection mode
808286 is high speed processor compared with 8086. almost 6 times
Push , pop and push immediately instructions are availabe
Features of 80386 It is an 32 bit processor that supports 8,16 and 32-bit operands. It has 32 bit registers , 32 bit internal and external bus and 32
bit address busDue to 32 bit address bus, it can address up to 4 GB of physical
memory It can support total virtual memory space almost 64 terra byte It is available in 275 K transistors Its operating clock speed is 16 Mhz to 33MhzThis processor has memory management unit with a
segmentation unit and paging unit It operates in Real, Protected and virtual mode Its 80386 instructions set is upward compatible with all its
predecessors80386 processor supports intel 80387 numeric data processor.
Comparison between 80286 and 8038680286 80386 Intel 80286 was developed
in 1983 and it is advanced version of 80186
16 bit processor134K transistor in a 68 pin
IC24 bit address lines , 16
MB of physical memory can be accessed
80286 support numeric processors
8 byte prefetch queue
Intel 80386 was developed in 1985 and it is advanced version of 80286
32 bit processor275K transistor in 132 pin
IC32 bit data and 32 bit
address lines , 4GB of physical address it can support
Supports numeric processors
It is having 16 byte prefetch queue
Features of 80486It has complete 32 bit architectureIt is available in 25 Mhz, 33Mhz, 50Mhz and 100Mhz
clock frequency versionsMore pipe lining has been introduced to improve the
performanceFloating point unit is integrated with 80486 processor
and hence the delay in communication between CPU and FPU has been eliminated
For fast execution of complex instructions, 80486 has 5 stage pipelining 2- decoding and 3 for execution
Clock doubling and clock tripling technology is incorporated in faster versions of intel 80486 cpu
Power management mode is standard feature of 80486
Pentium ProcessorsFeatures
5V processor fabricates in 0.8micron BiCMOS technology
Runs at a clock frequency of 60Mhz/66Mhz and has 3.1 millon transistor
Compatibility with 80386 instructions through a micro programmed CISC unit
It is Super scalar architectureWider 64 bit data buswith pipelined burst mode for
quicker chache line fills and write backsTwo independent integer pipelines and a floating
point pipelineMemory management unit availablePower save function is also available
Block diagram of Pentium architecture
Pentium ProThis is 6th generation processor introduced in
1995It consists of 5.5 million transistorsThis is able to work in dual-processor and quad-
processor configurations.It has 12 stage pipeline architecture36 address bus8KB instruction Cache2 integer units and 1 floating point unitThis are popular in multiprocessing configurationsP6 architure operates in 32 bit OS such as UnixIt operates on 3.1V to 3.3 V