I/O CONTROLLER

PURPOSE:To control respective I/O devices by performing state control over the I/O devices by a general interface driver supported by the OS of a controller. CONSTITUTION:The operation states of the I/O devices 7a-7n are monitored by a local processor 41 at all times and their state changes are sequentially stored in an I/O status register 3. central processing part 1 reads the I/O status register 3 to know the states of the I/O devices 7a-7n. Only when abnormality which can not be handled by the local processor 41 occurs to one of the I/O devices 7a-7n, that is reported to the central processing part 1 through an interruption processing part 44 to put the processing into the charge of the central processing part 1.