What id the PIC18 RAM Address for the registers PCU and PCHS

What id the PIC18 RAM Address for the registers PCU and PCH?

Solution

PIC microcontrollers have many registers for arithmetic and logic operations. The PIC18 program counter is 21 bits wide. Low byte is the PCL register. The high byte is PCH register. This register contains the PC<15:8> bits which is not directly readable or writeable.PCLATH register is used to perform updates on PCH registers.

The upper byte is called the PCU register which contains the PC<20:16> bits and is not directly readable or writeable. Updates on PCU can be performed through PCLATU register.