21.5.5 Register Write Protection

To prevent any single software error from corrupting PIT64B behavior, certain registers in the address space can be write-protected by setting the WPEN (Write Protection Enable), WPITEN (Write Protection Interrupt Enable), and/or WPCREN (Write Protection Control Enable) bits in the PIT64B Write Protection Mode Register (PIT64B_WPMR).

If a write access to a write-protected register is detected, the WPVS (Write Protection Violation Status) flag in the PIT64B Write Protection Status Register (PIT64B_WPSR) is set and the WPVSRC (Write Protection Violation Source) field indicates the register in which the write access has been attempted.

The WPVS bit is automatically cleared after reading PIT64B_WPSR.

The following registers can be write-protected when WPEN is set in PIT64B_WPMR:

• PIT64B Mode Register
• PIT64B LSB Period Register
• PIT64B MSB Period Register

The following registers can be write-protected when WPITEN is set in PIT64B_WPMR:

• PIT64B Interrupt Enable Register
• PIT64B Interrupt Disable Register

The following register can be write-protected when WPCREN is set in PIT64B_WPMR:

• PIT64B Control Register