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Sunday, February 26, 2012

Difference between MAX and MIN mode


Maximum mode
Minimum Mode
When MN/MX(bar) low 8086 is in maximum mode.
When MN/MX(bar) high 8086 is in minimum mode.
In maximum mode 8086 generates QS1,QS0,S0(bar),S1(bar),S2(bar), LOCK(bar),RQ(bar)/GT1,RQ(bar)/GT0 control signals.
In minimum mode 8086 generates INTA(bar), ALE, DEN(bar), DT/R(bar), M/IO(bar), HLDA,HOLD and WR(bar) control signals.
So clearly there are multiple processors in the system.
There is only one processor in the system minimum mode.
Whereas in maximum mode interfacing, master/slave and multiplexing and several such control signals are required

In maximum mode a bus controller is required to produce control signals. This bus controller produces MEMRDC, MEMWRC, IORDC, IOWRC, ALE, DEN, DT/R control signals.
In minimum mode no interfacing or master/slave signals is required.


In minimum mode direct RD WR signals can be used. No bus controller required. A simple demultiplexer would do the job. of producing the control signals. This demultiplexer produces MEMRD, MEMWR, IORD, IOWR control signals.
Maximum mode 8086 system

Minimum mode 8086 System

5 comments:

  1. third point is wrong......
    there is single processor in mim mode....
    while multiple processor in max mode...

    ReplyDelete
    Replies
    1. Thank you Diya for pointing out the errors. So i have updated the post with correct points an some more points. Thank you again.

      Delete
  2. thanks, it is some useful information

    ReplyDelete
    Replies
    1. you are welcome... keep visiting....

      Delete
  3. Aren't ALE,DEN,DTR found in min mode?

    This point is confusing:


    This bus controller produces MEMRDC, MEMWRC, IORDC, IOWRC, ALE, DEN, DT/R control signals.

    ReplyDelete