| 摘要 |
PURPOSE:To inform stack abnormalities by generating detect signals when contents of the stack pointer which changes the content in accordance with the number of characteristic of evacuating programs to be stored in the stack memory do not coincide with preset contents. CONSTITUTION:When the program being executed is evacuated because a processing, such as interruption, is generated during the course of program execution of a processing section 12, its characteristic (e.g. the return address when the evacuating program is returns) is planted in a stack memory 13, and a stack pointer 1 is a counter for example, whose content is processed every time when the above mentioned returning address is set, and is used for address designation when evacuated programs are called. When the content of the stack pointer 1 becomes more than or less than contents of an upper limit and lower limit registers 2 and 3, respectively at comparators 4 and 5, the content of the stack pointer 1 is output as interrupt signals 9 and 10 after detect signals 15 and 16 are respectively generated. In this way, destructions of program process can be prevented. |
