S3F84B8_UM_REV 1.00 5 INTERRUPT STRUCTURE5-45.1.5.1 Interrupt Vector AddressesAll interrupt vector addresses for the S3F84B8 interrupt structure is stored in the vector address area of first 256bytes of the program memory (ROM).You can allocate unused locations in the vector address area as normal program memory. However, do notoverwrite any of the stored vector addresses.The default program reset address in the ROM is 0100H.16,383(Decimal)16K-byteProgram MemoryArea3FFFH(HEX)0255Interrupt VectorAddress Area00H100HFFHDefaultResetAddressFigure 5-3 ROM Vector Address Area5.1.5.2 Enable/Disable Interrupt Instructions (EI, DI)Executing the Enable Interrupts (EI) instruction enables the interrupt structure globally. All interrupts are thenserviced as they occur, according to the established priorities.NOTE: The system initialization routine executed after a reset must always contain an EI instruction to globally enable theinterrupt structure.During the normal operation, you can execute the Disable Interrupt (DI) instruction at any time to disable interruptprocessing globally. The EI and DI instructions change the value of bit 0 in the SYM register.
