status register are connected to the data bus. The status register contains information relevant to the operation of the I/O module.
The status register is a hardware register that contains information about the state of the processor. Individual bits are implicitly or explicitly read and/or written by the machine code instructions executing on the processor. The status register lets an instruction take action contingent on the outcome of a previous instruction.
Typically, flags in the status register are modified as effects of arithmetic and bit manipulation operations. A status register may often have other fields as well, such as more specialized flags, interrupt enable bits, and similar types of information.