Lec-8: Instruction in 8085 | 1B, 2B & 3B Instructions | Opcode & Operand | Microprocessor

Summary

The video script is an educational tutorial focusing on the 8085 microprocessor and its instruction set. It explains how instructions are executed based on specific data and timing, emphasizing the importance of synchronization. The presenter uses simple language to clarify complex concepts, such as the difference between one-byte, two-byte, and three-byte instructions, and how they are stored in memory. The script also covers the encoding of instructions, with examples like 'MOV' and 'ADD', and their hexadecimal representations. The tutorial is designed to help viewers understand the microprocessor's architecture and how to program it effectively.

Takeaways

• 😀 The video explains the functioning of the 8085 microprocessor, focusing on instruction execution and timing.
• 👨‍🏫 The presenter uses simple language and hand gestures to illustrate how the microprocessor performs tasks based on instructions.
• 📝 The script discusses the concept of instructions in the context of the 8085 microprocessor, emphasizing the importance of timing and data manipulation.
• 💡 It is highlighted that the 8085 microprocessor can execute a variety of instructions, ranging from 1 to 3 bytes in size.
• 🔢 The video script explains how instructions are categorized based on the number of bytes they occupy, such as 1-byte, 2-byte, and 3-byte instructions.
• 📖 The presenter provides examples of how instructions are stored in memory, including the use of hexadecimal codes and addressing.
• 💻 The script delves into the process of executing instructions, including moving data into the accumulator and performing operations like addition.
• 🔧 The video explains the concept of opcodes, which are numerical representations used by the microprocessor to understand and execute instructions.
• 📐 The script also covers the memory addressing scheme of the 8085, which can reference up to 64 kilobytes of memory.
• 🔄 The video script illustrates the process of storing data in memory locations, including the breakdown of memory addresses into lower and upper bytes.

Q & A

What is the main topic of the video?

The main topic of the video is explaining the instructions in the 8085 microprocessor.

What does the acronym 'IT' refer to in the context of the video?

In the video, 'IT' refers to 'Instruction Timing', which is about the timing of tasks performed by the microprocessor.

What is the significance of '1/8' and '2/3' instructions mentioned in the video?

The '1/8' and '2/3' instructions refer to the size of the instructions in bytes, indicating the memory space they occupy.

What does the term 'accumulator' mean in the context of the 8085 microprocessor?

The 'accumulator' is a register within the 8085 microprocessor used for storing and manipulating data.

How does the video describe the process of executing commands in the 8085 microprocessor?

The video describes the process as a series of actions performed by the microprocessor based on the instructions, which also involves timing.

What is the default instruction size if no operation is specified in the 8085?

If no operation is specified, the default instruction size in the 8085 is one byte.

What is the maximum number of instructions the 8085 microprocessor can generate?

The 8085 microprocessor can generate up to 256 different instructions.

How are instructions represented in hexadecimal in the 8085 microprocessor?

Instructions in the 8085 microprocessor are represented in hexadecimal, with each instruction having a specific code.

What is the purpose of the 'MOV' instruction mentioned in the video?

The 'MOV' instruction is used to move data into the accumulator from memory or an input/output device.

How does the video explain the concept of memory addressing in the 8085?

The video explains memory addressing by discussing how 16-bit addresses are used to reference memory locations, with each location storing 8 bits.

What is the significance of the 'STC' instruction in the 8085 microprocessor?

The 'STC' instruction is used to set the carry flag in the 8085 microprocessor, which is used for arithmetic and logical operations.