arithmetic for computers
play

Arithmetic for Computers October 31, 2008 Arithmetic for Computers - PowerPoint PPT Presentation

Arithmetic for Computers October 31, 2008 Arithmetic for Computers ALU Arithmetic Logic Unit Performs most processor operations Control signal predicates addition subtraction logic operations shifting (w / or w / o sign extension) Figure:


  1. Arithmetic for Computers October 31, 2008 Arithmetic for Computers

  2. ALU Arithmetic Logic Unit Performs most processor operations Control signal predicates addition subtraction logic operations shifting (w / or w / o sign extension) Figure: ALU symbol Arithmetic for Computers

  3. Multiplication Product of n with m bits = n + m bits long More complicated than addition use addition with shifting shift left 1 bit to align with previous sum Arithmetic for Computers

  4. Multiplication Product of n with m bits = n + m bits long More complicated than addition use addition with shifting shift left 1 bit to align with previous sum Figure: Hardware for multiplication 64-bit multiplicand reg.: ∵ will be moved 32 times 32-bit multiplicand in right half; left half: 0‘s Product: initialized to 0‘s Arithmetic for Computers

  5. Multiplication Algorithm Figure: Multiplication using the simple hardware Arithmetic for Computers

  6. Improvement Problem: need 64-bit adder Half bits in multiplicand are 0 Improvement: Don’t shift the multiplicand Shift product right ! Add it to product on the left Shift product to right Figure: Improved hardware Arithmetic for Computers

  7. New Algorithm Arithmetic for Computers

  8. Another Improvement Save on space: Put multiplier in product saves on speed: only single shift needed Figure: Improved hardware for multiplication Arithmetic for Computers

Download Presentation
Download Policy: The content available on the website is offered to you 'AS IS' for your personal information and use only. It cannot be commercialized, licensed, or distributed on other websites without prior consent from the author. To download a presentation, simply click this link. If you encounter any difficulties during the download process, it's possible that the publisher has removed the file from their server.

Recommend


More recommend