Answer to Question #273653 in Electrical Engineering for Rocky

Question

 What do you mean by IOP? Explain the concept of CPU-IOP communication with the help of its flow chart. Draw appropriate diagram also. 

Answer 1

Intraocular pressure (IOP) is the fluid pressure of the eye. As pressure is a measure of force per area, IOP is a measurement involving the magnitude of the force exerted by the aqueous humor on the internal surface area of the anterior eye.

To conduct tasks related to computer architecture, there is a communication link between IOP and CPU. This channel describes the commands executed by the IOP and CPU while running dome applications. The CPU does not execute the instructions; instead, it gives the duty of beginning activities to IOP, who executes the instructions. The CPU directs I/O transfer. The IOP requests the CPU through interrupt.

This channel is initiated by the CPU by sending the "test IOP route" instruction to IOP, after which communication occurs as illustrated in the diagram:

When the CPU receives an interrupt from the IOP to access memory, it sends a test path instruction to the IOP. IOP executes and checks for status; if the status returned to the CPU is OK, the CPU issues a start instruction to IOP, giving it some control, and returns to another (or the same) program; after that, IOP is allowed to access memory for its program.

Now, IOP will begin regulating I/O transfers through DMA and will provide a new status report. As soon as this I/O transfer is completed, IOP sends an interrupt to the CPU, the CPU requests the status of the IOP, and IOP checks the status word from memory and returns it to the CPU. Now the CPU double-checks the state and repeats the operation.