Q. 54 The 8255 Programmable Peripheral Interface is used as described below.
(i) An A/D converter is interface to a microprocessor through an 8255.
The conversion is initiated by a signal from the 8255 on Port C. A signal on Port
C causes data to be stobed into Port A.
(ii) Two computers exchange data using a pair of 8255s. Port A works as a
bidirectional data port supported by appropriate handshaking signals.
The appropriate modes of operation of the 8255 for (i) and (ii) would be
(A) Mode 0 for (i) and Mode 1 for (ii)
(B) Mode 1 for (i) and Mode 2 for (ii)
(C) Mode for (i) and Mode 0 for (ii)
(D) Mode 2 for (i) and Mode 1 for (ii)
Answer: (D)
Explanation:
