28.3.1. Program Counter Changes

So, the threes codes for LDA store and load add and store are this one. That is the opcode is 000 means that it is a load instruction add means 1000 and 0001 for store.

In this chunk, we discuss the basic instructions in a hypothetical assembly language along with their associated opcodes. The opcode represents the operation that the CPU needs to perform. For example, '000' is identified as a load operation where a value is transferred from memory to a register like the accumulator, '1000' corresponds to an add operation, and '0001' indicates a store operation which saves data back to memory.

Think of the opcode as a recipe name in a cookbook. Just like a recipe tells you what dish you are about to make (e.g., salad, pasta), the opcode tells the CPU which operation to perform. If '000' is akin to a 'load' recipe, it means that the CPU will begin by fetching ingredients (data) from storage (memory) to prepare its dish (execute operations).

And then this is where you have to load the value is FF0. So, this one is going to be the binary. So, if somebody erases this and say this is your first line of code, 000 very difficult to read and understand therefore, we always keep the memories. So, in this case the instruction size is 4 instruction size is 4 + 12 that is 4 × 4 16 bits.

This segment introduces the concept of instruction size in the context of memory. It highlights that an instruction consists of a certain number of bits, with a calculation leading to a total of 16 bits. The instruction size signifies how much data can be processed at one time, which directly impacts how the instructions are stored and executed within the CPU. The value 'FF0' is specified, which is the memory address where the data associated with the operation must be loaded from.

Consider the instruction size as the size of a box you use to store items. A larger box (16 bits) can hold more items (data), making it easier and more efficient to manage. On the other hand, if the box is too small (like a 4-bit instruction), you might have to constantly change boxes, leading to confusion and more effort to keep track of what you have.

So, this one is done, memory buffer register it is the instruction register, it is decoded and it knows what to do, and you can understand that program PC is actually program counter has changed to next instruction to be executed.

Here we learn about the single address format used in instructions. The memory buffer register temporarily holds the value fetched from memory before it is sent to the instruction register where it is decoded to determine its function. After executing one instruction, the program counter (PC) update to point to the next instruction. This ensures that instructions are processed in sequence, allowing the CPU to systematically execute programs.

Imagine you're following a series of steps in a game. Each time you complete a step (instruction), you check off your list to move to the next one. The PC behaves like your pointer on that list, leading you to the next action without losing track of your progress.

Now, we see step wise basically what happens, now we will again deal with we have already discussed a similar example beforehand, but now we will see in more depth of the different instructions, even registers and the formats.

This chunk explains how arithmetic operations, such as addition, are performed using the values stored in registers, the accumulator, and memory locations. The chunk indicates that the steps involved will be broken down further to simplify understanding of how these components interact during execution, focusing on registers that temporarily hold data through this process.

Think of it as solving a mathematical problem where you need to carry numbers between sheets of paper (registers) and a blackboard (memory). You first gather numbers on the paper (load them), draw temporary calculations on the blackboard (perform additions), and finally write an answer back on the original paper (store results) to keep your solution organized.

So, if you look at it. So, what happened? So, the first case the value of program counter was this, the next the value of program counter is next 3F1 and after that the value of program counter becomes 3F2 that is it goes step by step.

This part further discusses the flow of the program counter as it goes through various instruction addresses. As the CPU executes instructions, the program counter keeps track of where the CPU is in the instruction sequence. After executing an instruction, the PC updates to the next instruction's address, whether it's to progress linearly or jump based on control instructions.

Imagine you're reading a book where each page represents an instruction. When you finish reading a page, you simply turn to the next one (incrementing the PC). However, if you decide to skip to a chapter, you would jump ahead—similarly, the PC adjusts based on conditional instructions.

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