19.11 Register Write Protection

To prevent any single software error from corrupting MATRIX behavior, certain registers in the address space can be write-protected by setting the WPEN bit in the Write Protection Mode Register (MATRIX_WPMR).

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

The WPVS flag is reset by writing the Write Protect Mode Register (MATRIX_WPMR) with the appropriate access key WPKEY.

The following registers can be write-protected:

• Bus Matrix Host Configuration Registers
• Bus Matrix Client Configuration Registers
• Bus Matrix Priority Registers A For Clients
• Bus Matrix Priority Registers B For Clients
• Host Error Interrupt Enable Register
• Host Error Interrupt Disable Register
• Security Client Registers
• Security Areas Split Client Registers
• Security Region Top Client Registers
• Security Peripheral Select x Registers