Programmed 10--P29 Issue Re ad command to CPL→LO IAO module ☆Ⅳ O module performs the action,not Read status the processor vO IO→CPU module ☆ Sets app ropriate bits in the vo Error status register status condition Ready ☆ No interrupts occur Read word from vc IO→CP Module Processor checks status until Write word operation is complete CP→ memor into memory ☆Busy- waits Yes Next instruction (a) Programmed IO DEVICE MANAGEMENTDEVICE MANAGEMENT Programmed I/O --P29. ❖I/O module performs the action, not the processor ❖Sets appropriate bits in the I/O status register ❖No interrupts occur ❖Processor checks status until operation is complete ❖Busy-waits