8255 Programmable Peripheral Interface

8255 Programmable Peripheral Interface

PERIPHERAL INTERFACING  PPI INTERFACING ! ! !

Peripheral Interfacing i" con"i#ere# to be a main part of $icroproce""or% a" it i" the onl& 'a& to interact 'ith the e(ternal 'orl#) The interfacing happen" 'ith the port" of the $icroproce""or) $icroproce""or) The main IC*" 'hich are to be interface# 'ith 8+85 are, -) 8255 PPI 2) 825. PIC /) 825- 01ART ) 823. 4e& boar# #i"pla& controller  5) 825/ Timer Co6nter  7) A an# A con9erter interfacing)

! The 8255 i" a pop6lar interfacing component% that can interface an& TTLcompatible I: #e9ice to a microproce""or) ! It i" 6"e# to interface to the ;e&boar# an# a parallel printer port in PC" 6ire" a "ingle ?5@ "6ppl&) !  The 8255 ha" three port", PortA% Port an# PortC)

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PortA can be programme# to 'or; in an& one of the three operating mo#e" mo#e+% mo#e- an# mo#e2 a" inp6t or o6tp6t port)

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Port can be programme# to 'or; either in mo#e+ or mo#e- a" inp6t or o6tp6t port)

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PortC