6.2.2. Synthesis Objectives

First it is a comprehensive objective you will be able to describe about the control steps and control signals needed to execute an instruction this is one of the most important part of this module. That will give an instruction sometimes I will call it macro instruction to differentiate it from the micro instructions. So, if I give you an instruction like I say that load accumulator 3030. So, you will be able to tell me what are the exact control steps and what is the exact control sequence required to do it.

This objective focuses on understanding the essential control steps and signals necessary for executing an instruction within a computer's control unit. When given a command, like loading a value into a register, students are expected to articulate the specific steps the computer takes to carry out that command. This involves delving into both high-level instructions, often referred to as macro instructions, and the fundamental-level operations, called micro instructions, needed to achieve the task.

Imagine a chef following a recipe to cook a dish. The recipe represents the macro instruction (e.g., "make a salad"), while the detailed actions (e.g., "chop vegetables," "mix dressing") are akin to the micro instructions. Just as the chef must follow these steps to successfully create the dish, a computer must follow its control steps to execute an instruction.

This is a synthesis objective. Synthesis objective says that design issues of control steps of the basic instructions like read memory for execution with reference to a given organization. That means you will able to design a system or a computing control unit system, with given to a given organization; that means, if it is a single bus or multiple bus, then you will be able to design the control steps required.

In this part of the synthesis objectives, students are encouraged to understand the design factors that influence how control steps are created based on different system architectures. For instance, if a system uses a single bus architecture, the design must account for the limitations and methods of managing data transfer through that single path. Conversely, with multiple buses, the design can be more efficient because it allows for multiple simultaneous data transfers. Students must be able to conceptualize how to create the necessary signals and steps tailored to these architectures.

Think of a traffic intersection. In a simpler design with one traffic light (single bus), traffic must take turns, leading to potential delays. In a complex design with multiple traffic lights (multiple buses), cars can move simultaneously in various directions, improving efficiency. Students need to understand how to manage the flow of control signals, much like how traffic signals control vehicle movement.

Of course, you will be also able to design that is another synthesis objective design instruction for control operations like branch function call etcetera.

Here, students are tasked with designing specific instructions that handle control operations, such as branching, function calls, and other critical tasks in program execution. This objective reinforces the understanding of how to manage different control flows within a program, particularly when dealing with conditional execution or calls to functions. Students will learn to think critically about how these operations are integrated into the overall control system.

Consider a computer program like a choose-your-own-adventure book where readers make choices that affect the story's outcome. Each choice represents a branching operation, directing the flow of the story based on the reader's preferences. Similarly, in programming, control instructions direct the execution flow based on conditions that must be met, much like choosing a path in a story.

Then of course, 2 important things you will be able to design this control signal based on hardwire based control unit and micro program based control unit that is the hardware business as well as software business.

In this section, the focus is on the generation of control signals in different types of control units. Students will explore hardwired control units, where signals are fixed and predetermined by the hardware configuration, and microprogrammed control units, which allow for more flexibility through programmable control signals. This understanding is essential for students to design effective control units that can accommodate various instructions and processing architectures.

Imagine a remote control that operates a TV. A hardwired remote has fixed buttons (hardwired control), while a programmable remote can have its settings changed to operate different devices (microprogrammed control). Similarly, understanding how to design control signals allows for both rigid and flexible systems in computing.

And the last instruction is again a design instruction. So, you design issues for implementation of the micro program as well as your hardwired control unit you will be able to design both, compare among them both and find out which is the more optimized implementation at any point of time.

The final synthesis objective encourages students to compare and contrast hardwired and microprogrammed control unit designs. By evaluating their respective advantages and disadvantages, students will gain insights into when each design is appropriate for use. They will learn to assess performance, efficiency, and suitability of each type depending on specific application needs, leading to the ability to choose the most optimized solution.

Consider the difference between a custom-built sports car (hardwired) designed for speed and a versatile family car (microprogrammed) that can accommodate many passengers. Each has its strengths, and by comparing them, students can determine which type of design serves a particular purpose better, just like deciding on a vehicle based on specific travel needs.

--