Intel 8255A - Pin Description - Tutorialspoint This block is responsible for controlling the internal/external transfer of data/control/status word. It accepts the input from the CPU address and control buses, and in turn issues command to both the control groups. CS. It stands for Chip Select. A LOW on this input selects the chip and enables the communication between the 8255A and the CPU. Programmable peripheral interface (8255): Architecture Mar 01, 2017Programmable peripheral interface (8255) 1 Architecture of 8255 . The parallel input-output port chip 8255 is also called as programmable peripheral input- output port. The Intel’s 8255 is designed for use with Intel’s 8-bit, 16-bit and higher capability microprocessors.