- · l Receiving device CPU instructions: CPU read and write instructions and parameters are stored in the control register
- · l Report the status of the device to the CPU: There will be a corresponding status register in the I/O controller to record the current status of the I/O device. (For example, 1 means the device is busy, 0 means the device is ready)
- · l Data exchange: data register, which temporarily stores the data sent by the CPU and the data sent by the device, and then sends the data to the control register or CPU.
- · l Address recognition: Similar to the memory address, in order to distinguish each register in the device controller, it is necessary to set a specific address for each register. The I/O controller uses the address provided by the CPU to determine which register the CPU wants to read and write.
|I/O controller chip||CH423|