THERM_MAXTEMP_OUTRANGE_ALERT is used at the device
level in order to generate device warm reset. The alert is asserted when the device
overheats and exceeds the maximum temperature limit specified for the device, namely
125°C.
The following is the sequence to assert the
THERM_MAXTEMP_OUTRANGE_ALERT:
- For the output to go active (‘1’), the VTM has to
be configured to operate with at least one of its temperature sensors enabled,
and WKUP_VTM_TMPSENS_CTRL_j[11] MAXT_OUTRG_EN = 1 for the corresponding enabled
sensor.
- In addition, WKUP_VTM_MISC_CTRL[0]
ANYMAXT_OUTRG_ALERT_EN has to be set to ‘1’.
- With the previous configuration set and at least
one of the temperature sensors properly configured, and enabled, if the
temperature of the die ever exceeds the programmed value in WKUP_VTM_MISC_CTRL2,
the VTM output will be driven ‘1’ once the sensor detects the programmed maximum
temperature.
- At the device level the VTM output,
THERM_MAXTEMP_OUTRANGE_ALERT, will drive the PLL controllers into warm reset
state with the PLL controllers entering warm reset condition, at the same time that all the PLLs go into clock
bypass mode.
- By the actions described in No.4, the device will considerably reduce its power consumption, which over the passing of a few seconds will cause the device to reduce its temperature.
- The VTM sensor continues to read the temperature
and once the code corresponding to the programmed value in
WKUP_VTM_MISC_CTRL2[25-16] MAXT_OUTRG_ALERT_THR0 is detected the VTM drives
THERM_MAXTEMP_OUTRANGE_ALERT = 0.
- After No.6 is fulfilled, the PLL controllers no
longer have the THERM_MAXTEMP_OUTRANGE_ALERT driving the warm reset request and thus the PLL controllers bring the SoC out of
reset and the boot sequence re-starts. At the same time the PLLs get out of
bypass mode and start with their target programmed frequencies for the boot
process.
Note: THERM_MAXTEMP_OUTRANGE_ALERT output of VTM is
mapped to WKUP_VTM_MISC_CTRL[0] ANY_MAXT_OUTRG_ALERT_EN.
Notice that exceeding of the programmed value in
WKUP_VTM_MISC_CTRL2[9-0] MAXT_OUTRG_ALERT_THR boundary doesn’t result in a PORz
(cold reset) event, but instead a warm
reset event. Otherwise if cold reset is applied to the MCU/WKUP domains of
the device, the VTM will be fully reset and the output THERM_MAXTEMP_OUTRANGE_ALERT
will be cleared to ‘0’ immediately.