ML610Q174 User’s ManualChapter 2 CPU and Memory SpaceFEUL610Q174-01 2-12. CPU and Memory Space2.1 OverviewThis LSI incorporates 8-bit CPU nX-U8/100, and a LARGE model is selected for the memory model.For details of the CPU nX-U8/100, refer to the “nX-U8/100 Core Instruction Manual”.2.2 Program Memory SpaceThe program memory space is used to store program codes, table data (ROM window), or vector tables.The program codes have a length of 16 bits and are specified by a 16-bit program counter (PC).The ROM window area contains data having a length of 8 bits and can be used as table data.The vector table, which has 16-bit long data, can be used as reset vectors, hardware interrupt vectors, and softwareinterrupt vectors.The program memory space consists of 2 segment and has a total capacity of 128 Kbytes (64 Kwords).Figure 2-1 shows the configuration of the program memory space.CSR:PCSegment 00:0000H～0FFFFH CSR:PCSegment 11:0000H～0FFFFH0:0FFFFH0:0FC00H Test data area0:0FBFFH0:0100HProgram codeorROM window area0:00FFH0:0000HVector table area,program code,orROM window area1:0FFFFH1:0000HProgram codeorROM window area8bit 8bitFigure 2-1 Configuration of Program Memory SpaceNotes:• The 1K-byte (512-word) test data area (0:FC00H to 0:FFFFH) of Segment 0 is a test data area. Out of the test dataarea, the area 0:FC00H to 0:FDFFH is writable and erasable and the area 0:FE00H to 0:FFFFH is disabled for bothwrite and erase. The area 0:FC00H to 0:FDFFH is an ISP boot area. When use it as an ISP boot area, write in aboot program by an on-chip ICE function. Set Code-Option in the area 0:FDE0H, and always write "0FFH" in thearea 0:FDE2H to 0:FDFFH. Operation is not guaranteed if the state where it does not write in or any other value than“0FFH” is written.• Set “0FFH” data (BRK instruction) in the unused area of the program memory space for fail-safe reasons.
