GCBASIC documentation
Port control

Syntax:

    LOCKPPS

Explanation:

Peripheral Pin Select (PPS) has an operation mode in which all input and output selections can be prevented to stop inadvertent changes.

PPS selections are locked by setting by the use of the LockPPS command.

Using this command will ensure the special sequence of Microchip assembler is handled correctly.

Command Availability:

Available on all Microchip microcontrollers only.

    #chip 16f18855,32
    #option explicit

    'Set the PPS of the I2C and the RS232 ports.
    #startup InitPPS, 85
    Sub InitPPS
      UNLOCKPPS
        RC0PPS = 0x0010       'RC0->EUSART:TX;
        RXPPS  = 0x0011       'RC1->EUSART:RX;

        SSP1CLKPPS = 0x14     'RC3->MSSP1:SCL1;
        SSP1DATPPS = 0x13     'RC4->MSSP1:SDA1;
        RC3PPS = 0x15         'RC3->MSSP1:SCL1;
        RC4PPS = 0x14         'RC4->MSSP1:SDA1;
      LOCKPPS          ' <<< the LockPPS instruction
    End Sub

Key line: LOCKPPS — re-locks the PPS registers once the pin assignments above have been made, preventing further inadvertent changes.

See Also: