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3.3 BASE AREA
The space from 0 to FFFFH comprises the base area. The base area is the object for the following uses:
• Reset entry address
• Interrupt entry address
• CALLT instruction entry address
• 16-bit immediate addressing mode (with instruction address addressing)
• 16-bit direct addressing mode
• 16-bit register addressing mode (with instruction address addressing)
• 16-bit register indirect addressing mode
• Short direct 16-bit memory indirect addressing mode
The vector table area, CALLT instruction table area and CALLF instruction entry area are allocated to the base area.
When the LOCATION 0H instruction is executed, the internal data area is located in the base area. Note that, in the internal
data area, program fetches cannot be performed from the internal high-speed RAM area or special function register (SFR) area.
Also, internal RAM area data should only be used after initialization has been performed.
3.3.1 Vector Table Area
The 64-byte area from 00000H to 0003FH is reserved as the vector table area. The vector table area stores the program
start addresses used when a branch is made as the result of RESET input or generation of an interrupt request. When context
switching is used by an interrupt, the number of the register bank to be switched to is stored here.
Any portion not used as the vector table can be used as program memory or data memory.
16-bit values can be written to the vector table. Therefore, branches can only be made within the base area.
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CHAPTER 3 CPU ARCHITECTURE
User's Manual U11316EJ4V1UD
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