SPRUJ79 November 2024 F29H850TU , F29H859TU-Q1
For diagnostics of safety mechanisms, ECC logic needs to be checked periodically. However, running test-of-diagnostics in software to check ECC logic is time consuming as many patterns have to be run to get to the required coverage. To enable seamless diagnostics, self-test logic is added.
The self-test controller generates test sequences to detect faults in ECC logic. Any errors found as part of the test sequences is logged into self-test configuration registers that are part of the PIPE module. Different data patterns can be required to get additional coverage. The input data and ECC values to the ECC logic is programmable through self-test registers.
If at any point the software reads the INT_VECT_ADDR registers to perform ECC checks on the read vector address value, any enabled self-test sequences are paused. Software is required to continually poll for the completion status of the self-test sequences to account for such pauses.
The self-test controller can run the following test sequences, see Figure 6-4, to detect an error in ECC logic:
If any of these checks fails, then self-test execution is aborted. The SELFTEST_DIAG_STATUS register can be read to check for these errors.
Programming sequence for self-test controller:
Refer to PIPE Self-Test registers for additional details.