8255 PPI (Programmable Peripheral Interface) | Architecture, Pin Diagram & Modes Explained

A simplified and comprehensive explanation of its architecture and programming. This lecture is perfect for B.Tech, Diploma, and competitive exam aspirants (GATE/IES) looking to master I/O interfacing. What you will learn in this session: Introduction to 8255A PPI and its necessity in 8085 interfacing. Detailed analysis of the 8255 internal Block Diagram. Functional groups: Group A and Group B control logic. Port organization: Understanding Port A, Port B, and Port C (Upper & Lower). The Control Word Register and its critical role. Overview of Operating Modes: BSR (Bit Set Reset) and I/O Modes (Mode 0, 1, 2). Introduction to 8255 programming and initialization. Video Timestamps (Click Points) [00:00] Introduction to 8255 PPI [01:21] Why we use 8255 with 8085 Microprocessor [03:00] Features of 8255: 40-Pin IC Overview [03:45] Internal Architecture & Block Diagram [04:40] Data Bus Buffer & Read/Write Control Logic [05:40] Functional Groups: Group A and Group B Control [07:32] Internal Registers and the Control Word Register [08:45] Pinout Details: CS, A0, A1, and Data Pins [10:08] Hardware Interfacing with Microprocessor [11:15] Programming the 8255: Basic Concept [12:16] Operating Modes: BSR vs. I/O Mode [13:17] Deep Dive: BSR (Bit Set Reset) Mode [15:30] How to write the Control Word for BSR Mode [17:15] I/O Mode Overview: Modes 0, 1, and 2 [18:15] Mode 0: Basic Input/Output Configuration [20:00] Control Word Format for I/O Modes [20:50] Conclusion and Summary #8255PPI #8255Architecture #MicroprocessorInterfacing #8085Microprocessor #BSRMode #EngineeringLectures #ElectronicsEngineering #TechTutorial #GATEPreparation #ClassesSimplified