STORAGE PROTECTION SYSTEM

摘要

PURPOSE:To easily attain the protection of storage in an extension area without changing the address setting way in a basic area by providing at least two pairs of address range designating registers. CONSTITUTION:A pair of address range designating registers 3 and 2 set the upper and lower limit addresses where the programs stored in a basic area are available. Meanwhile at least a pair of address range designating registers 5 and 4 set the upper and lower addresses where the programs included in an extension area, etc., are available. Then an access grant signal is transmitted for execution of an access when an access address is kept in a range of a pair of registers 5 and 2 or registers 5 and 4.