9.4.7.7 Fault Injection Tests

Trip Point Override Test

This test shows that monitored sources will trigger OV/UV Faults if threshold limits are tightened.

Procedure:

  1. Wait for WRALLOW = 1.
  2. Adjust trip points via FLTUVSEL[4:0] and FLTOVSEL[4:0].
  3. Set the FLTOVUV bit to enable Fault injection.
  4. The system continues scanning all regular sources.
  5. The Fault status appears in the VMxSTAT register.

If a Fault is detected:

  • The corresponding VMxEVENT bit is set.
  • If FLTRSTEN = 1: a device Reset will occur on the first detected Fault, and the FLTRST status bit is set.
  • If FLTRSTEN = 0: no device Reset occurs.
Note: The test is executed once per activation; the FLTOVUV bit auto-clears after one round-robin cycle. This prevents the system from remaining in a reduced monitoring state after the test.
Figure 9-5. Overriding Trip Point Voltages While Scanning Regular Sources

Low Power Enable

At the completion of the round-robin scan sequence, low power is asserted for the duration configured through SCANPS[2:0] settings. Once the low-power period expires, the mode is deasserted. Note that there is no low-power period when SCANPS[2:0] = 0. While in Low-Power mode, the bandgap and the oscillator continue to run. It is expected that the mode reduces current consumption from 130 μA to approximately 80 μA.

Interrupts

There is one interrupt associated with the Power Monitor module.

  • PWRMIE – Power Monitor Interrupt Enable bit
  • PWRMIF – Power Monitor Interrupt Flag - set high when round-robin source scan is complete. It also coincides with the WRALLOW bit being set to indicate Fault settings can safely be adjusted.
  • PWRMIP – Power Monitor Interrupt Priority bit