Processor Status Word

Learning Outcomes

1.Understand the importance of processor status registers in modern computing systems and their role in instruction execution.

2.Gain detailed knowledge of status flags such as Zero (Z), Carry (C), Overflow (O), Sign (S), and Parity (even/odd), along with their influence on decision-making processes in instructions.

3.Learn to design and model a status register and integrate it effectively into a basic processor architecture.

4.Acquire skills to design and simulate digital circuits using tools like Logisim.

5.Explore the interaction between the control unit and the status register during operation execution for better synchronization and performance.

Tasks

1.Understand the Concept of Status Registers

1. • Research how processors like ARM, x86, and RISC-V utilize status registers to store operational flags.

   • Identify common flags (e.g., Zero, Carry, Overflow, Sign) and understand their specific purposes.

2.Design the Status Register

1. • Define the architecture of a basic status register tailored to specific processor needs.

   • Determine the number and type of flags required for efficient functionality.

   • Develop a truth table to clearly outline the logic for setting or clearing flags based on different operations.

3.Integrate with the Arithmetic Logic Unit (ALU)

1. • Establish a connection between the status register and the ALU to record outcomes of arithmetic and logical operations.

   • Implement logic to dynamically update flags based on the results generated by the ALU.

4.Implement Error Handling

1. • Design logic using specific flags to detect and handle errors, such as division by zero or invalid operations.

   • Ensure the processor can signal errors appropriately and take corrective measures when required.