1 / 24

Instruction Set Architecture

Instruction Set Architecture. Stephen Murphy. What is ISA?. Aspects of the computer visible to the programmer: Data Types Registers Instructions Addressing. Data Types. Unsigned Integers Signed Integers Characters Floating-point Numbers. Unsigned Integers.

heath
Télécharger la présentation

Instruction Set Architecture

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Instruction Set Architecture Stephen Murphy

  2. What is ISA? Aspects of the computer visible to the programmer: • Data Types • Registers • Instructions • Addressing

  3. Data Types • Unsigned Integers • Signed Integers • Characters • Floating-point Numbers

  4. Unsigned Integers • Stores the integer in standard binary format 00101011 = 1 + 2 + 8 + 32 = 43

  5. Signed Integers • Stores the integer in two’s complement format to denote sign Steps to convert signed integer to base 10: • Store leading bit, 1 = negative, 0 = positive • Invert all bits • Add 1

  6. Characters • Represented by integer values Many different character encodings exist: • ASCII • UNICODE • UTF-8 • UTF-16

  7. Floating-point Numbers Four components in a floating-point number: • Sign • Mantissa • Radix • Exponent

  8. Registers Registers provide a variety of services: • Instruction Counter • Register-to-Register Operations • Memory-to-Register Operations • Memory-to-Memory Operations • Processor Status

  9. Instruction Counter Register • All von Neumann machines have an instruction counter which is a register

  10. Register-to-Register Registers • Operate on one register using another register (ADD) • Supported by all ISA’s

  11. Memory-to-Register Registers • Operate on memory using a register (LOAD, STORE) • Not supported by all ISA’s

  12. Memory-to-Memory Registers • Operate on one memory location using another memory location (STRCMP) • Not supported by all ISA’s

  13. Processor Status Registers • A collection of registers that indicate the current state of the processor (Carry, Interrupt, Zero) • Different ISA’s use different status registers

  14. Instructions Categories of instructions: • Operate • Memory Access • Control • Miscellaneous

  15. Operate Instructions Typical operations include: • Arithmetic (ADD, SUB, MUL, DIV) • Logical (AND, OR, NOT, XOR) • Shift (ROL, ROR) • Character (STRCMP) • Stack (PUSH, POP)

  16. Memory Access Instructions Typical operations include: • Load (LODSB) • Store (STOSB)

  17. Control Instructions • Conditional Branch (JZ, JC, JO, JS) • Unconditional Branch (JMP)

  18. Miscellaneous Instructions • Input/Output (IN, OUT) • Interrupts (CLI, INT, IRET) • Halt • Privileged

  19. Addressing • Register Addressing • Memory Addressing

  20. Register Addressing • When an operand is taken from a register it is called register addressing

  21. Memory Addressing • Logical Address Space (sequential memory locations) • Physical Address Space (many types exists: absolute addressing, indirect addressing, etc.)

  22. ISA Examples • MIPS • Motorola 6800 • ARM • SPARC • PowerPC • x86 • IA-64

  23. ISA Humor • BOB – Branch On Bug • ADN – Add Nauseam • BPDI – Be Polite, Don’t Interrupt • BPE – Bypass Program Error • DMNS – Do what I Mean, Not what I Say • DC – Divide and Conquer • CDHI – Crash Disk Head Immediately

  24. References • http://webster.cs.ucr.edu/AoA/Windows/HTML/ISA.html • http://www.wordiq.com/definition/Instruction_set • http://www.cs.panam.edu/~meng/Course/CS4335/Notes/master/node22.html

More Related