SPRUIZ1B July 2023 – August 2024 TMS320F28P650DH , TMS320F28P650DK , TMS320F28P650SH , TMS320F28P650SK , TMS320F28P659DH-Q1 , TMS320F28P659DK-Q1 , TMS320F28P659SH-Q1
The self-test of the comparator has two different modes:
These two tests are run together. Self-test is initiated by setting the appropriate register bit (LCM_CONTROL.STEN). When the self-test is initiated, the two different modes are executed on the two comparators one after the other. A self-test error triggers error aggregator logic at the SoC. A failed self-test also generates an NMI.
Redundant instantiation of the comparator block allows for one instantiation to be conducting a self-test while the other instantiation is active and performing the comparison check.
Self-test can also be performed before the comparator block is enabled in software.
Execution of the self-test is stopped immediately on failure. If either comparator fails the self-test, a status bit (LCM_STATUS.STPASS) is 0 instead of being set to 1.
During self-test, the LCM_STATUS.STACTIVE bit has a value of 1. Another self-test or compare error force must not be started until completion of the self-test, as indicated by LCM_STATUS.STDONE = 1.
The following subsections describe functionality of each of the individual test modes, Mismatch Test and Match Test.