Question

Compare any three attributes of 80386 and 80486 Microprocessor

Answer 1

80386 :
(1) The INTEL’s 80386 is a 32-bit microprocessor introduced in 1985.
(2) 80386 is a logical extension of 80286. It is more highly  pipelined.
(3) The instruction set of 80386 is a superset of other members of 8086 family.
(4) It has 32-bit data bus and 32-bit nonmultiplexed address bus. It can address a physical memory of 232 i.e. 4 Gbytes. The 80386 memory mangement allows it to address 246 or 64 Tbytes.
(5) The 386 can be operated in one of the following memory  management modes:
(a) Paged mode
(b) Non- paged mode.
(6) When operated in paged mode, the 386 switches the paging unit then after the segment unit. The paging unit allows memory pages of 4 KB each to be swapped in and out from disk. In non
- paged mode, memory mangement unit operates very similar to the 286.
(7) Virtual addresses are represented with selected components and an offset component as they are with 80286.
80486 :
(1) Intel’s 80486 is a 32-bit microprocessor. It has 32-bit address bus and 32-bit data bus. It was introduced in 1989.
(2) The 486 is basically a large integral circuit which contains a fast built-in, a math coprocessor, a memory mangement unit (M.M.U), and an 8 kbyte cache memory.
(3) 80486 has DX and SX versions.
(4) All 486 processor have 32-bit data bus. SX version does not have on chip- numeric coprocessor.
(5) The 486 achieves its high speed operation from its faster clock  speeds, internal pipe lined architecture and the use of reduced  instruction set computing (RISC) to speed up the internal 
microcode. 
(6) 486 also has 486 DX2 and 486 DX4 versions, with double and triple clock speed.