In order to change the contents of a protected I/O register the CCP register must first be written with the correct signature. After CCP is written the protected I/O registers may be written to during the next four CPU instruction cycles. All interrupts are ignored during these cycles. After these cycles interrupts are automatically handled again by the CPU, and any pending interrupts will be executed according to their priority.

When the protected I/O register signature is written, CCP[0] will read as one as long as the protected feature is enabled, while CCP[7:1] will always read as zero.

CCP[7:1] only have write access. CCP[0] has both read and write access.