Configuration registers are typically configured in the beginning and hold the value till the particular task execution. Periodic read back of configuration registers can provide a diagnostic for inadvertent writes or disturb of these registers.

The diagnostic coverage can be improved by extending the test to include read back of the flag registers that are expected to remain constant (for example, PLL lock status, EQEP phase error flag, and so forth) during the device operation as well. Error response, diagnostic testability, and any necessary software requirements are defined by the software implemented by the system integrator.

The diagnostic coverage of some peripherals can be further enhanced by applying some module specific tests as follows:

• For improving the enhanced peripheral interrupt expander (EPIE) coverage, the PIE flag registers can be periodically checked to ensure that all pending interrupts are serviced by reading the PIE flag registers (PIE_CTRL_REGS.PIEIFRx.all) and the peripheral interrupt flag registers.
• While serving the interrupt, the ISR routine can check for flag setting in peripheral as well as PIE to ensure that correct interrupt is being serviced.

Since CLA configuration registers are accessible to C28x CPU only, this safety mechanism for CLA module has to be executed by C28x CPU.