JPS6446856A - Expanding system for extension memory - Google Patents

Abstract

PURPOSE:To avoid such a case where the memory extension capacity of a system is mistakenly decided based on the memory extension capacity set at the designing time point of a basic device, by expanding the memory capacity within an extension memory device to cope with the multiple tasks. CONSTITUTION:An address register circuit 1 stores the data used when a logical address is converted into a physical address for each task. An extension memory circuit 2 uses the output of the circuit 1 as an input. A task register circuit 3 obtains a task number for actuation from a system bus to store it and supplies the storage output to the circuit 1. Then a control circuit 4 controls the circuits 1-3 respectively. The memory capacity is expanded within an extension memory device to cope with the multiple tasks. Thus it is possible to avoid such a case where the memory extension capacity of a system is mistakenly decided based on the memory extension capacity set at the designing time point of a basic device.