Explain input output control word format of 8255. Write control word of 8255 to initialize Port A as input port, Port B and C as output port, Group A and B in Mode 0.

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written 6.1 years ago by

meghalikalyankar • 2.3k

• modified 5.1 years ago

microprocessors and peripherals

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written 6.1 years ago by

meghalikalyankar • 2.3k

To do 8-bit data transfer using the Ports A, B or C, 8255 needs to be in the IO mode. The bit pattern for the control word in the IO mode is as follows:

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Calculation of CWR to initialize Port A as input port, Port B and C as output port, Group A and B in Mode 0.

enter image description here CWR = (90H)

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