Stack pointer management

摘要

A processor (100) is provided that is a programmable digital signal processor (DSP) with variable instruction length. offering both high code density and easy programming. Architecture and instruction set are optimized for low power consumption and high efficiency execution of DSP algorithms, such as for wireless telephones, as well as pure control tasks. A user stack region (910) is used to pass variables to a subroutine and to hold values representative of a first portion of a program counter (1000). A system stack region (911) is used to hold values representative of a remaining portion of the program counter (1001) and to hold additional context information. The user stack region and the system stack region are managed independently so that software from a prior generation processor can be translated to run on processor (100).