Interrupt Vector Addresses - Samsung S3F84B8 User Manual

S3F84B8_UM_REV 1.00

5.1.5.1 Interrupt Vector Addresses

All interrupt vector addresses for the S3F84B8 interrupt structure is stored in the vector address area of first 256
bytes of the program memory (ROM).
You can allocate unused locations in the vector address area as normal program memory. However, do not
overwrite any of the stored vector addresses.
The default program reset address in the ROM is 0100H.
5.1.5.2 Enable/Disable Interrupt Instructions (EI, DI)
Executing the Enable Interrupts (EI) instruction enables the interrupt structure globally. All interrupts are then
serviced 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 the
interrupt structure.
During the normal operation, you can execute the Disable Interrupt (DI) instruction at any time to disable interrupt
processing globally. The EI and DI instructions change the value of bit 0 in the SYM register.
(Decimal)
16,383
16K-byte
Program Memory
Area
255
Interrupt Vector
Address Area
0
Figure 5-3
(HEX)
3FFFH
100H
FFH
00H
ROM Vector Address Area
5-4
5 INTERRUPT STRUCTURE
Default
Reset
Address