Question

The IC 8255 is a

• A. Address Decoder
• B. Programmable Peripheral Interface
• C. Direct Memory Access controller
• D. EPROM

Hint:

8255 PPI is a versatile I/O interface chip.
It provides programmable parallel I/O ports.
Commonly used in microprocessor-based systems for interfacing with peripherals.

Answer 1

The Correct Option is B

The Intel 8255 (or 82C55) is a widely used Programmable Peripheral Interface (PPI) chip. It is designed to interface peripheral devices with the microprocessor system bus. Key features of the 8255:
It provides 24 programmable I/O pins, typically organized into three 8-bit ports (Port A, Port B, and Port C).
These ports can be programmed in different modes of operation (Mode 0: Basic I/O, Mode 1: Strobed I/O, Mode 2: Bidirectional Bus).
It allows the microprocessor to control and communicate with various types of peripheral devices like keyboards, displays, printers, ADCs, DACs, etc. (a) Address Decoder: Decodes addresses but is not the primary function of 8255. (c) Direct Memory Access (DMA) controller: This is typically a different chip (e.g., 8237, 8257). (d) EPROM (Erasable Programmable Read-Only Memory): This is a type of non-volatile memory. Therefore, the IC 8255 is a Programmable Peripheral Interface. \[ \boxed{\text{Programmable Peripheral Interface}} \]