Some questions on microprocessors

Discussion in 'Homework Help' started by kush.impetus, Dec 6, 2010.

  1. kush.impetus

    Thread Starter New Member

    Dec 6, 2010
    Hi all!

    I have some questions on 8085 microprocessor.

    1. What is the working area in CPU?
    2. How do we find the 1-byte, 2-byte and 3-byte instructions from the instruction set of 8085?
    3. Is machine cycle simply more that execution cycle or is double of it?
    4. What is the maximum number of I/O devices addressable by 8085?

    Thanks in advance

    Kumar Kush
  2. RiJoRI

    Well-Known Member

    Aug 15, 2007
    If you get the Intel 8085 User Manual it will answer all your questions, and many others.

    I've not used an 8085 in over 20 years, but that little book was a life-saver!

  3. BillO

    Distinguished Member

    Nov 24, 2008
    No idea what you mean here. All of the CPU is utlized and works. Could you be more specific or give more detail?

    This tells all :

    There are various execution cycles for the 8085. Refer to the Intel datasheet for them. They give diagrams for all 5 types of execution cycles.

    The 8085 has 256 non-memory mapped I/O addresses. In addition, you could have a theoretical maximum of 65,536 memory mapped I/O addresses. In practical terms this would, of course, be limited by the amount of memory you needed for RAM and program space. On top of all this, you could page I/O to any extent you wanted. So, with a little work, I/O could be unlimited.