Configuration Bytes

The devices have 10 Configuration Bytes, starting at address 30 0000h. The Configuration bits enable or disable specific features, placing these controls outside the normal software process, and they establish configured values prior to the execution of any software.

In terms of programming, consider the following Configuration bits:
  1. 1.LVP: Low-Voltage Programming Enable bit
    • 1 = ON: Low-Voltage Programming is enabled. MCLR/VPP pin function is MCLR. The 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, refer to Low-Voltage Programming (LVP) Mode.
  2. 2.MCLRE: Master Clear (MCLR) Enable bit
    • If LVP = 1: RA3 pin function is MCLR
    • If LVP = 0
      • 1 = RA3 pin is MCLR
      • 0 = RA3 pin function is a port-defined function
  3. 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 the Code Protection section.