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
at

17 comments:

  1. Divya RawatMay 21, 2012 at 12:53 AM

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

    ReplyDelete
    Replies
    1. k10bloggerMay 25, 2012 at 10:21 PM

      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. UnknownApril 11, 2017 at 3:25 PM

      microprocessor padha do naaaa....divya

      Delete
  2. venkat siva reddyMay 24, 2013 at 10:36 AM

    thanks, it is some useful information

    ReplyDelete
  3. UnknownAugust 9, 2013 at 8:33 AM

    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
  4. UnknownDecember 10, 2015 at 9:44 PM

    why is there bar over certain pins in 8086? What does tat indicate? please help

    ReplyDelete
    Replies
    1. AkanshaDecember 10, 2015 at 11:41 PM

      Bar indicates active low signals.
      These signals will be 'ON' on input 0 bit and 'OFF' on input 1bit.

      Delete
    2. AkanshaDecember 10, 2015 at 11:53 PM

      Bar indicates active low signals.
      These signals will be 'ON' on input 0 bit and 'OFF' on input 1bit.

      Delete
    3. UnknownDecember 11, 2015 at 7:14 PM

      Thank you Akansha. Do that mean MX (bar) indicates MAX mode is applicable only when the input bit is 0? If so, what will happen at pin 26 or pin 29 when the input is 1?

      Delete
    4. UnknownMay 7, 2016 at 10:09 PM

      For some signals to get output without any delay we try to give ACTIVE LOW signals.So,if you find any BAR on any pin of mp/mc then it means tgat it is ACTIVE LOW...

      Delete
    5. UnknownMay 7, 2016 at 10:11 PM

      For some signals to get output without any delay we try to give ACTIVE LOW signals.So,if you find any BAR on any pin of mp/mc then it means tgat it is ACTIVE LOW...

      Delete
  5. UnknownApril 8, 2016 at 7:01 PM

    The diag is taken from which text book

    ReplyDelete
    Replies
    1. UnknownApril 17, 2016 at 3:54 PM

      Advanced Microprocessors and Peripherals by AK Ray and KM Bhurchandi.

      Delete
  6. UnknownMay 11, 2016 at 12:42 AM

    It is noted that in minimum mode, the processor cannot be accessed by other master. So what is the importance of HOLD and HLDA pin in 8086 minimum mode configuration?

    ReplyDelete
  7. UnknownNovember 13, 2016 at 3:36 PM

    where memory read is use?. minimum or maximum mode??

    ReplyDelete
  8. UnknownJune 15, 2017 at 2:13 PM

    Can anyone please tell me what is the purpose of using minimum and maximum mode? Where it is used?

    ReplyDelete