SPRUJ79 November 2024 F29H850TU , F29H859TU-Q1
The error pin monitor event indicates that the err_i and err_o pins (input and output to the ESM, respectively) have differed for eight or more consecutive cycles. This detects if the error pin connectivity external to the ESM is malfunctioning.
ERR_I is stored, in case previous values of ERR_I are either all 0's or 1's, the previous 8 values of ERR_O is checked for atleast one match. If there is no match between previous 8 values of ERR_I and ERR_O, this indicates that the external connection from ERR_O back to ERR_I is malfunctioning. Error Pin Monitor event/interrupt is triggered only if all values of ERR_I being equal (all zeroes or ones) and stored ERR_O values being the logical inverse (all zeroes or ones). The above mechanism provides immunity against glitches or pin transitions triggering spurious pin monitor interrupt outputs. PWM low and high counters values need to be greater than 8 cycles when using pwm mode for error pin monitor to detect a malfunctioning ERR_I.
When an error pin monitor interrupt occurs, a processor handling this interrupt logs or alerts the external system associated with error pin monitoring. This interrupt can be enabled/disabled via the Error Pin Monitor Config Register and set or cleared via Error Pin Monitor Interrupt Status/Set Register and Error Pin Monitor Interrupt Status/Clear Register respectively.
A software write of the EOI vector to the EOI Interrupt Register also results in a re-evaluation of the error pin monitor interrupt/event.