DYNAMIC STACK CONSTITUTION CONTROLLING DEVICE

PURPOSE:To improve efficiency of use of an expensive high speed large capacity memory by utilizing effectively an address smaller than the smallest address of an effective stack area as a data storage area separate from the stack area. CONSTITUTION:The increase and decrease of the capacity of an empty area provided in a continuous storage area 10A of stack constitution is detected by a data pointer register 22 and a stack pointer register 21, and judged by an address comparator 41, and at the same time, storage and release of data are made between a data storage area 12 and an external storage device 30. Thus, unused area of stack can be recognized dynamically, and at the same time, a stack constitution controlling device having a data storage area can be obtained.