8085 Architecture | Learn Intel 8085 Microprocessor Architecture Step - By - Step

Summary

This tutorial offers an in-depth exploration of the Intel 8085 microprocessor architecture, ideal for computer science students. It covers the 8085's history, technical specifications, and its five major functional units, including the memory unit, ALU, instruction decoder, timing and control unit, and interrupts. The video simplifies complex concepts, such as the instruction cycle and flag register, and explains the 8085's bus architecture, making it easier to grasp foundational microprocessor concepts.

Takeaways

• 😀 The Intel 8085 microprocessor was one of the first 8-bit processors launched by Intel in 1976 and remains in use today.
• 📚 Studying the 8085 architecture is fundamental for computer science students as it provides a basis for understanding more complex microprocessor architectures.
• 💡 The microprocessor's main function is to execute programs, which are sets of instructions directing the CPU to perform operations.
• 🔍 The instruction cycle of the CPU includes three steps: fetch, decode, and execute, which are repeated to perform program instructions.
• 🔧 The 8085 microprocessor architecture can be broken down into five major functional units: memory unit, ALU, instruction decoder, timing and control unit, and interrupts and serial communication unit.
• 🔢 The 8085 is an 8-bit processor with a 40-pin configuration, operating on a +5V supply and available in 3.5 MHz and 6 MHz execution speed variants.
• 📈 It has an 8-bit data bus and a 16-bit address bus, allowing it to address up to 64 kilobytes of memory.
• 🔑 The 8085 features 6 general-purpose 8-bit registers (B, C, D, E, H, L) and special-purpose registers for specific functions during instruction execution.
• 🚀 The accumulator, part of the ALU, is used to store operands and perform arithmetic and logical operations as per the decoded operation code.
• 📊 The flag register, or program status word (PSW), is an 8-bit register indicating the CPU status after ALU operations, using flags like carry, auxiliary carry, sign, parity, and zero.
• 🔄 The timing and control unit generates clock pulses and control signals to synchronize the operations of internal components and manage external hardware devices.

Q & A

What is the 8085 microprocessor and when was it launched by Intel?

The 8085 microprocessor is an 8-bit processor launched by Intel Corporation in 1976. It was one of the first 8-bit processors and is still in use today in many devices.

Why is it important for computer science students to study the 8085 architecture?

Studying the 8085 architecture is important for computer science students as it helps them understand foundational concepts necessary to study more complex microprocessor architectures and how CPUs work.

What is the basic operation of a CPU called?

The basic operation of a CPU is called the instruction cycle, which includes fetch, decode, and execute operations.

What are the five major functional units of the 8085 microprocessor?

The five major functional units of the 8085 microprocessor are the memory unit (register unit), the arithmetic and logic unit (ALU), the instruction decoder and machine cycle encoder unit, the timing and control unit, and the interrupts and serial communication unit.

What is the purpose of the Program Counter (PC) register in the 8085 architecture?

The Program Counter (PC) register is a 16-bit special purpose register used to store the address of the instruction that needs to be fetched from memory.

What is the role of the Accumulator register in the 8085 processor?

The Accumulator register is part of the Arithmetic and Logic Unit (ALU) and stores the operand part of the instruction format for performing arithmetic and logical operations.

What does the Flag Register indicate in the 8085 architecture?

The Flag Register, also known as the Program Status Word (PSW), is an 8-bit special purpose register that indicates the status of the processor after each ALU operation, such as carry, sign, zero, auxiliary carry, and parity.

What are the functions of the Timing and Control Unit in the 8085 microprocessor?

The Timing and Control Unit generates clock pulses and control signals to synchronize the operations of the CPU's internal components and manage the operations of various hardware devices connected to the system.

How many types of interrupts does the 8085 architecture support?

The 8085 architecture supports eight software interrupts and five hardware interrupts.

What are the three main components of the 8085 bus architecture?

The three main components of the 8085 bus architecture are the address bus, the data bus, and the control bus.

What is the significance of the data bus in the 8085 architecture?

The data bus in the 8085 architecture is an 8-bit bi-directional bus used to transfer data between the CPU and the main memory RAM during memory read and write operations.