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~National
~ Semiconductor
APRIL 1978
INS8255 Programmable Peripheral Interface
General Description
The INS8255 is a programmable peripheral interface contained in a standard, 4().pin dual·in·line package. The chip, which is fabricated using N·charinel silicon gate technology, functions as a general·purpose parallel input/output interface in National Semiconductor's N8080 microcomputer family. The functional configura· tion of the INS8255 is programmed by the system software so that normally no external logic is required to interface peripheral devices.
The INS8255 has three basic modes of operation that can be selected by the system software. In the first mode (Mode 0), the INS8255 provides simple input and outqut operations for three 8·bit ports.
INS8255N Datasheet
