METHOD AND DEVICE FOR ACCESSING CHIP SELECTION ENABLE DEVICE IN DATA PROCESSING SYSTEM

摘要

PROBLEM TO BE SOLVED: To utilize the internal chip selection/write enable occurrence logic when an external master accesses an external memory without setting the access timing of the external master at the timing equal to or later by one cycle than that of an internal master. SOLUTION: A user can program a data processor so as to set an external master chip selection address at the length equal to or different from an internal master access by means of a control register 810. The user also can turn off the internal transfer acknowledge logic and also can add the external transfer acknowledge logic while using the internal chip selection/write enable occurrence logic 8 of the data processor. Owing to this feature, the user can program the data processor based on the selection of chips and also can compensate the different external master accesses without requiring the external chip selection/write enable logic.