Evolution of Instruction Sets

Evolution of Instruction Sets
Instruction Set Architecture (ISA) Abstract interface between the Hardware and lowest-level Software

• 1950: Single Accumulator: EDSAC
• 1953: Accumulator plus Index Registers:  Manchester Mark I, IBM 700 series
• Separation of programming Model from implementation:
           *  1963: High-level language Based:  B5000
           *  1964: Concept of a Family:  IBM 360
• General Purpose Register Machines:

         * 1977-1980:  CISC - Complex Instruction Sets computer:  Vax,   Intel 432
         * 1963-1976:  Load/Store Architecture:  CDC 6600,  Cray 1
         * 1987: RISC: Reduced Instruction Set Computer:  Mips,  Sparc,  HP-PA,  IBM RS6000

Typical RISC:

• Simple, no complex addressing
• Constant length instruction, 32-bit fixed format
• Large register file
• Hard wired control unit, no need for micro programming
• Just about every opposites of CISC

Major advances in computer architecture are typically associated with landmark instruction set designs. Computer architecture's definition itself has been through bit changes. The following are the main concern for computer architecture through different times:

• 1930-1950: Computer arithmetic
       * Microprogramming
       * Pipelining
       * Cache
       * Timeshared multiprocessor
• 1960: Operating system support, especially memory management
      * Virtual memory
• 1970-1980: Instruction Set Design, especially for compilers; Vector processing and shared memory multiprocessors
      * RISC
• 1990s: Design of CPU, memory system, I/O system, multi-processors, networks
     * CC-UMA multiprocessor
     * CC-NUMA multiprocessor
     * Not-CC-NUMA multiprocessor
     * Message-passing multiprocessor
• 2000s: Special purpose architecture, functionally reconfigurable,special considerations for low power/mobile processing, chip multiprocessors, memory systems
    * Massive SIMD 
    * Parallel processing multiprocessor

Under a rapidly changing set of forces, computer technology keeps at dramatic change, for example:

• Processor clock rate at about 20% increase a year
• Logic capacity at about 30% increase a year
• Memory speed at about 10% increase a year
• Memory capacity at about 60% increase a year
• Cost per bit improves about 25% a year
• The disk capacity increase at 60% a year.