The Processor Status Word (PSW) is a critical register in a processor that holds flags and control bits which provide vital information about the processor's current state during program execution. The PSW contains several key status flags, such as the Zero Flag (indicating whether the result of an operation is zero), the Carry Flag (indicating if there was a carry or borrow in arithmetic operations), the Sign Flag (showing if the result is negative), and the Overflow Flag (indicating an overflow in signed operations). Additionally, it includes control bits that manage the processor's operations, such as enabling or disabling interrupts and determining the current processor mode (e.g., user mode or supervisor mode). The PSW is essential for decision-making in program control, as it allows conditional instructions to execute based on the status flags, and it is critical during context switching in multitasking systems, as it preserves the processor's state. By providing this status information, the PSW ensures that the processor can handle branching, interrupts, and operations correctly, allowing for smooth and accurate program execution.
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