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MINIMUM MODE 8086 SYSTEM

In a minimum mode 8086 system, the

microprocessor 8086 is operated in minimum modeby strapping its MN/MX pin to logic 1.

In this mode, all the control signals are given out by

the microprocessor chip itsel. !here is a single

microprocessor in the minimum mode system.

!he remaining components in the system are

latches, transreceivers, cloc" generator, memory

and I/# devices. $ome type o chip selection logicmay be re%uired or selecting memory or I/#

devices, depending upon the address map o the

system.

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&atches are generally buered output '(type lip(

lops li"e )*&$+)+ or 88. !hey are used or

separating the valid address rom the multiple-edaddress/data signals and are controlled by the

& signal generated by 8086.

!ransreceivers 886 are the bidirectionalbuers and some times they are called as data

ampliiers. !hey are re%uired to separate the

valid data rom the time multiple-ed address/data

signals.

!hey are controlled by t2o signals namely, 'N

and '!/34.

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!he 'N signal indicates the direction o

data, i.e. rom or to the processor. !he systemcontains memory or the monitor and users

program storage.

5sually, 3#M are used or monitorstorage, 2hile 3M or users program

storage. system may contain I/# devices.

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Maximum Mode 8086 System

In the ma-imum mode, the 8086 is operated by strapping the MN/MX

pin to ground.

In this mode, the processor derives the status signal $, $1, $0.

nother chip called bus controller derives the control signal using this

status inormation .

In the ma-imum mode, there may be more than one microprocessor

in the system coniguration.

!he components in the system are same as in the minimum modesystem.

!he basic unction o the bus controller chip I7 888, is to derive

control signals li"e 3' and 3 or memory and I/# devices, 'N,

'!/3, & etc. using the inormation by the processor on the status

lines.

http://8085projects.info/maximum-mode-8086-system.htmlhttp://8085projects.info/maximum-mode-8086-system.html

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Maximum Mode 8086 System

!he bus controller chip has

input lines $, $1, $0 and

7&9. !hese inputs to 888

are driven by 75.

It derives the outputs &,

'N, '!/3, M3'7,

M!7, M7, I#37,

I#7 and I#7. !heN, I#: and 7N pins

are specially useul or

multiprocessor systems.

http://8085projects.info/maximum-mode-8086-system.htmlhttp://8085projects.info/maximum-mode-8086-system.html

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Maximum Mode 8086 System; All these command signals instructs the memory to

accept or send data from or to the bus.

; For both of these write command signals, theadvanced signals namely AIOWC and AMWC are

available.

; !ere the only difference between in timing diagrambetween minimum mode and ma"imum mode isthe status signals used and the available controland advanced command signals.

http://8085projects.info/maximum-mode-8086-system.htmlhttp://8085projects.info/maximum-mode-8086-system.html

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8088 Microprocessor (8/16 bit)

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Memory interfacing in Minimum mode

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Memory interfacing in Maximum mode