2.5 Configuration Words

The devices have five Configuration Words starting at address 8007h. The Configuration bits enable or disable specific features, placing these controls outside the normal software process. They also establish configured values prior to the execution of any software.

In terms of programming, consider these important Configuration bits:
  1. LVP: Low-Voltage Programming Enable bit
    • 1 = ON: Low-Voltage Programming is enabled. MCLR/VPP pin function is MCLR. MCLRE Configuration bit is ignored.
    • 0 = OFF: High voltage on MCLR/VPP must be used for programming.
    Important: The LVP bit cannot be written (to ‘0’) while operating from the LVP programming interface. The purpose of this rule is to prevent the user from dropping out of LVP mode while programming from LVP mode, or accidentally eliminating LVP mode from the Configuration state. For more information, see Low-Voltage Programming (LVP) Mode.
  2. MCLRE: Master Clear (MCLR) Enable bit
    • If LVP = 1: RA3 pin function is MCLR
    • If LVP = 0
      • 1 = MCLR pin is MCLR
      • 0 = MCLR pin function is a port-defined function
  3. CP: User NVM Program Memory Code Protection bit
    • 1 = OFF: User NVM code protection is disabled
    • 0 = ON: User NVM code protection is enabled

For more information on code protection, see Code Protection.