71CHAPTER 2 DEPENDENCE FUNCTIONS2.2.1.4 Memory MappingMemory space can be allocated to the user memory, the emulation memory, etc., and theattributes of these areas can be specified.However, the MCU internal resources are not dependent on this mapping setup andaccess is always made to the internal resources.■ Access Attributes for Memory AreasThe access attributes shown in Table 2.2-2 can be specified for memory areas.A guarded memory access break occurs if access is attempted in violation of these attributes while executinga program.When access to the user memory area and the emulation memory area is made using program commands,such access is allowed regardless of the CODE, READ, WRITE attributes. However, access to memory withthe GUARD attribute in the undefined area, causes an error.When access is made to an area without the WRITE attribute by executing a program, a guarded access breakoccurs after the data has been rewritten if the access target is the user memory. However, if the access targetis the emulation memory, the break occurs before rewriting. In other words, write-protection (memory datacannot be overwritten by writing) can be set for the emulation memory area by not specifying the WRITEattribute for the area.This write-protection is only enabled for access made by executing a program, and is not applicable to accessby commands.■ Creating and Viewing Memory MapUse the following commands for memory mapping.SET MAP: Set memory map.SHOW MAP: Display memory map.CANCEL MAP: Change memory map setting to undefined.Table 2.2-2 Types of Access AttributesArea Attribute DescriptionUser MemoryEmulation MemoryCODE Instruction Execution EnabledREAD Data Read EnabledWRITE Data Write EnabledUndefined GUARD Access DisabledNOGUARD No check of access attribute
