Arm microcontrollers have linear memory organisation. Starting form 0x00000000 address to 0x40000000 is Internal Flash memory location. From 0x40000000 to 0x7FFFFFFF is on chip RAM memory space. As we know manu ARM families like LPC2000 series MCU is preprogrammed with flash boot-loader and ARM real monitor debug, so both are placed at location starting from 0x7FFFFFFF to 0x80000000 memory location.
Address space from 0x80000000 to 0xE0000000 is reserved for external memory.
Going up in memory space there is a peripheral memory space starting from 0xE0000000 to 0xE0200000. Each peripheral has its own memory page of 16Kbytes. Starting from 0xFFFFF000 there are Interrupt Unit located.
Interrupt vectors may be re-mapped to different memory locations like to RAM memory.