This text is structured as a slide-by-slide outline based on the standard curriculum from Ramesh Gaonkar's
Microprocessor Architecture, Programming, and Applications with the 8085. Slide 1: Title Slide
Microprocessor 8085: Architecture, Programming, and Interfacing Reference: Based on the works of Ramesh S. Gaonkar An Introduction to 8-bit Computing Slide 2: Introduction to 8085 Definition: An 8-bit, NMOS microprocessor. Key Features: 40-pin IC package. Operates on a single +5V DC supply. Max clock frequency of 3 MHz. 16-bit address bus (can address up to 64 KB of memory). 8-bit data bus. Vardhaman College of Engineering Slide 3: Internal Architecture Overview Three Main Units: ALU (Arithmetic Logic Unit):
Performs 8-bit operations like Addition, Subtraction, AND, OR, etc.. Registers: Temporary storage for data and addresses. Control Unit: Generates timing signals to coordinate all operations. Slideshare Slide 4: Register Organization Accumulator (A): The primary 8-bit register for ALU operations. General Purpose Registers:
B, C, D, E, H, and L (8-bit each; can be used as 16-bit pairs). Program Counter (PC):
16-bit register that holds the memory address of the next instruction. Stack Pointer (SP): 16-bit register used for stack memory management.
Carry (CY), Parity (P), Auxiliary Carry (AC), Zero (Z), and Sign (S). Slideshare Slide 5: The 8085 Bus System Address Bus (16-bit):
Unidirectional; determines which memory location or I/O device to access. Data Bus (8-bit):
Bidirectional; transfers data between the CPU and memory/IO. Multiplexing: The lower 8 bits of the address bus ( ) are multiplexed with the data bus ( ) to save pins, controlled by the ALE (Address Latch Enable) Vardhaman College of Engineering Slide 6: Addressing Modes Gaonkar classifies 8085 instructions into five modes: Immediate: Data is part of the instruction (e.g., MVI A, 05H Data is moved between registers (e.g., Address is specified in the instruction (e.g., Data is pointed to by a register pair (e.g., Implied/Implicit: The operand is hidden in the opcode (e.g., - Complement Accumulator). Slide 7: Interrupts Hardware Interrupts: Highest priority, non-maskable. RST 7.5, 6.5, 5.5: Vectored and maskable. General purpose, maskable. Software Interrupts: RST 0 through RST 7. Slide 8: Serial I/O Control Uses two dedicated pins for serial communication: SID (Serial Input Data): Read using the instruction. SOD (Serial Output Data): Set using the instruction. GeeksforGeeks UNIT I – 8085 MICROPROCESSOR
The 8085 Microprocessor is a landmark 8-bit chip, famously detailed in the textbook " microprocessor 8085 ppt by gaonkar
Microprocessor Architecture, Programming, and Applications with the 8085 " by Ramesh Gaonkar
. Below is a breakdown of the key concepts typically found in a PPT based on his work. ⚡ Core Architecture 8-Bit Processor: It processes 8 bits of data at once.
Address & Data Bus: Uses a 16-bit address bus (can access 64KB memory) and an 8-bit data bus. Multiplexing: The lower 8 bits of the address bus ( ) are multiplexed with the data bus to reduce pin count. Clock: Typically operates at a frequency of 3 MHz. 📊 Programming Model
Gaonkar’s model emphasizes the internal register structure:
Accumulator (A): An 8-bit register used for arithmetic and logic operations.
General Purpose: Six 8-bit registers (B, C, D, E, H, L) that can be used individually or in pairs (BC, DE, HL) to hold 16-bit data.
Flag Register: Contains five flip-flops (Sign, Zero, Auxiliary Carry, Parity, Carry) that reflect the status of the accumulator after an operation. 16-Bit Registers:
Program Counter (PC): Holds the address of the next instruction. Stack Pointer (SP): Manages the stack memory location. 🛠️ Instruction Groups The 8085 supports 74 basic instructions, categorized into:
Data Transfer: Moving data between registers or memory (e.g., MOV, MVI). This text is structured as a slide-by-slide outline
Arithmetic: Addition, subtraction, incrementing (e.g., ADD, SUB, INR).
Logical: AND, OR, XOR, and compare operations (e.g., ANA, ORA, CMP).
Branching: Jumping to different parts of the code (e.g., JMP, CALL, RET).
Machine Control: Controlling processor state (e.g., HLT, NOP). 🔍 Resources & Downloads
You can find full PPT slides and detailed notes based on Gaonkar's text at:
SlideShare: Includes a massive 330-slide deck specifically on the Gaonkar curriculum.
JECRC Foundation: Detailed PDFs covering the architecture and programming model.
School of Electrical Engineering: Academic PPT files outlining lab activities and core 8085 theory.
🚀 Key Takeaway: Gaonkar's approach focuses on understanding the timing diagrams and interfacing with I/O devices (like 8255 PPI) to make the microprocessor functional in real-world circuits. If you tell me, I can help further with: Specific instructions (e.g., how to use LDA vs LXI) Architecture (The Big Picture): Slides showing the internal
Timing diagrams (e.g., explaining T-states and Machine Cycles)
Interfacing chips (e.g., connecting the 8085 to 8259 or 8254) EEE226 - School of Electrical and Electronic Engineering
The 8085 microprocessor, developed by Intel in 1977, remains a foundational pillar for understanding computer architecture and assembly language programming. One of the most authoritative resources for mastering this chip is the textbook and supporting presentation materials by Ramesh S. Gaonkar, specifically his work titled "Microprocessor Architecture, Programming, and Applications with the 8085".
This guide synthesizes the core concepts found in Gaonkar’s 8085 presentations, focusing on internal architecture, the programming model, and system interfacing. 1. Introduction to the 8085 Microprocessor
The 8085 is an 8-bit, general-purpose microprocessor capable of addressing 64KB of memory. It was designed to be binary compatible with the earlier 8080 but with a simplified hardware design, requiring only a single +5V power supply.
Technology: Single NMOS chip with approximately 6,200 transistors.
Clock Speed: Typically operates at a maximum frequency of 3 MHz. Pins: A 40-pin Dual In-line Package (DIP). 2. Architecture and Functional Blocks
Gaonkar’s teaching model breaks down the 8085 into several critical functional units that work in tandem to execute instructions. Microprocessor 8085 complete | PPTX - Slideshare
Not all PowerPoints are created equal. The good ones (the ones derived directly from Gaonkar’s philosophy) usually contain these 6 core sections:
SID? Which is SOD? A good PPT highlights the multiplexed address/data bus (AD0-AD7).PUSH, POP, CALL, and RET work with the Stack Pointer (SP).An advanced Gaonkar PPT will go beyond the CPU:
Most students focus on parallel data transfer, but Gaonkar highlights a unique feature of the 8085: built-in serial communication.