Control Unit Implementation Factors Homework Answers
Your question:
Please give detailed explanation of the questions below.
Suppose you wanted to implement a control unit for a computer that you are designing.
Assignment Help Answers with Step-by-Step Explanation:
A hardwired control unit is designed using combinational logic circuits (such as gates and multiplexers) to generate control signals based on the opcode of the current instruction. Here's why you might choose a hardwired control unit:
Speed and Efficiency: Hardwired control units are generally faster because they directly generate control signals without the need for an intermediate microcode. This can be crucial for computers that require high processing speeds, such as supercomputers or gaming consoles.
Deterministic behavior.
Simple and small instruction set architectures.
Ease of Development: Designing a micro-programmed control unit can be less complex and more manageable for complex instruction set architectures (CISAs) or architectures with a large number of instructions. It's easier to debug and update microcode compared to altering hardware for every change.
Debugging and Testing: Microcode can be modified or patched to fix errors or vulnerabilities in the control unit without needing to modify the hardware. This can be crucial for maintaining the computer's functionality over time.
Support for multiple execution modes or privilege levels.
Factors Affecting the Decision:
In practice, many modern computers use a combination of both hardwired and micro-programmed control units to strike a balance between performance, flexibility, and ease of development.