CONFIG4

Configuration Word 4
Notes:
  1. 1.The LVP bit cannot be written (to zero) 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.
  2. 2.Once protection is enabled through ICSP or a self-write, it can only be reset through a Bulk Erase.
  3. 3.Applicable only if SAFEN = 0.
  4. 4.Applicable only if BBEN = 0.
  5. 5.BBSIZE[2:0] bits can only be changed when BBEN = 1. Once BBEN = 0, BBSIZE[2:0] can only be changed through a Bulk Erase.
  6. 6.The maximum Boot Block size is half of the user program memory size. Any selection that will exceed the half of a device’s program memory will default to a maximum Boot Block size of half PFM.
Name:
CONFIG4
Offset:
0x800A
Reset:
Access:
Bit15141312111098
LVPWRTSAFWRTDWRTCWRTB
AccessR/WR/WR/WR/WR/W
Reset11111
Bit76543210
WRTAPPSAFENBBENBBSIZE[2:0]
AccessR/WR/WR/WR/WR/WR/W
Reset111111

Bit 13 – LVP: Low-Voltage Programming Enable(1)

Low-Voltage Programming Enable(1)

ValueDescription
1 Low-Voltage Programming is enabled. MCLR/VPP pin function is MCLR. The MCLRE bit is ignored.
0 High voltage (HV) on MCLR/VPP must be used for programming

Bit 11 – WRTSAF: Storage Area Flash (SAF) Write Protection(2,3)

Storage Area Flash (SAF) Write Protection(2,3)

ValueDescription
1 SAF is not write-protected
0 SAF is write-protected

Bit 10 – WRTD: Data EEPROM Write Protection

Data EEPROM Write Protection

ValueDescription
1 Data EEPROM is not write-protected
0 Data EEPROM is write-protected

Bit 9 – WRTC: Configuration Registers Write Protection(2)

Configuration Registers Write Protection(2)

ValueDescription
1 Configuration registers are not write-protected
0 Configuration registers are write-protected

Bit 8 – WRTB: Boot Block Write Protection(2,4)

Boot Block Write Protection(2,4)

ValueDescription
1 Boot Block is not write-protected
0 Boot Block is write-protected

Bit 7 – WRTAPP: Application Block Write Protection(2)

Application Block Write Protection(2)

ValueDescription
1 Application Block is not write-protected
0 Application Block is write-protected

Bit 4 – SAFEN: Storage Area Flash (SAF) Enable(2)

Storage Area Flash (SAF) Enable(2)

ValueDescription
1 SAF is disabled
0 SAF is enabled

Bit 3 – BBEN: Boot Block Enable(2)

Boot Block Enable(2)

ValueDescription
1 Boot Block is disabled
0 Boot Block is enabled

Bits 2:0 – BBSIZE[2:0]: Boot Block Size Selection(5,6)

Boot Block Size Selection(5,6)

Table 1. Boot Block Size
BBEN BBSIZE End Address of Boot Block Boot Block Size (words)
PIC16F171x4 PIC16F171x5
1 xxx
0 111 01FFh 512
0 110 03FFh 1024
0 101 07FFh 2048
0 100 0FFFh (6) 4096
0 011 1FFFh (6)
0 010 3FFFh (6)
0 001 3FFFh (6)
0 000 3FFFh (6)