| 7.4 Vector List As described earlier, all exception handling routines employ the vector method to notify the CPU of the start address of the program to which execution is moved. Table 7.1 shows the list of exception handling vector addresses:
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The vector addresses are located in the area between H'000000 (start address of the memory space) and H'0000F3. This address area is called the "vector area". In this area, only data called "vectors" that represent the start address of each interrupt handling routine can be placed and no other data or program is allowed. The addresses marked "system reservation" in the table refer to free areas, which have no definite vectors to be placed. As described earlier, be sure to generate reset when turning the microcomputer on. Reset loads the reset vector stored in the reset vector addresses (between H'000000 and H'000003) within the vector area to the PC. In the reset vector addresses, the defined reset vector must have been stored before power-on. This means that the reset vector addresses must be in the ROM in which the reset vector is written. Whether to set other exception handling vector addresses in the ROM or RAM depends on the system. When using the microcomputer as an internal controller, however, other exception handling vector addresses are generally located in the same ROM as the reset vector addresses. |
