公开(公告)号：JPH11265287A

公开(公告)日：1999-09-28

申请号：JP30756398

申请日：1998-10-28

Applicant: MICROCHIP TECH INC

Inventor： ALLEN STEPHEN ,  WOJEWODA IGOR

IPC: G06F9/42 ,  G06F7/78 ,  G06F9/32 ,  G06F9/38

Abstract: PROBLEM TO BE SOLVED: To make predecodable the decrement value of a stack memory by selecting one of the next unused position in a stack memory device or a position immediately before the next unused position in the stack memory. SOLUTION: The stack pointer 12 is used for generating the next unused position in the stack memory device and indicating a place to write a present value in a program counter. The stack pointer 12 further generates the position immediately before the next unused position and reads the final value of the program counter written in the stack memory device. The next unused position in the stack memory device is selected for a write operation and the position immediately before the next unused position in the stack memory device is selected for a read operation. After executing a present instruction, the stack point 12 further performs one of the post increment or post decrement operations at the next unused position in the stack memory.