Program Memory Organization

PIC18 microcontrollers implement a 21-bit Program Counter, which is capable of addressing a 2 Mbyte program memory space. Accessing a location between the upper boundary of the physically implemented memory and the 2 Mbyte address will return all ‘0’s (a NOP instruction).

Refer to the following tables for device memory maps and code protection Configuration bits associated with the various sections of PFM.

The Reset vector address is at 000000h. The PIC18-Q20 devices feature a vectored interrupt controller with a dedicated interrupt vector table stored in the program memory. Refer to the “VIC - Vectored Interrupt Controller Module” chapter for more details.

Figure 1. Program and Data Memory Map