What is fixed interrupt vector table ?

[jani12]

Processor manual says the following:
"The fixed interrupt vector table is allocated to the addresses from 0xFFFDC to 0xFFFFF. Therefore, store the start address of each interrupt routine here."

The above address range is portion of internal ROM inside the microcontroller.
Why do they say "fixed". Can the vector table float ?

 

[Ian Rogers]

Unusual for the interrupt vectors to be high... Most micro's have interrupt vectors at the beginning of code space not the end... You must be working on 68HCxx micro...

They cannot be "floating" as the PC needs to know where they are.... When the interrupt occurs the "Address" of the interrupt routine is placed in these vectors... ( Someone may prove me wrong) but as far as I'm aware.... They are cast in stone..

 

[jani12]

Thank you for the reply. I'm working with Renesas M16C/6N5 Group Microcontroller.