SPRACZ5 December   2021 TDA4VM

 

  1.   Trademarks
  2. 1Introduction
  3. 2Enabling Thermal Shutdown Mandatory Step
  4. 3Thermal Mitigation Strategies at a High Level
    1. 3.1 Strategy 1: Auditing the Power Domains That Contribute to the Highest Power Consumption
    2. 3.2 Strategy 2: Disable Loading of Remote Core Firmware
    3. 3.3 Strategy 3: Disabling Modules on TDA4
      1. 3.3.1 Example: Disabling PCIe Instances on 7.3
    4. 3.4 Strategy 4: Dynamic Frequency Scaling (DFS)
    5. 3.5 Strategy 5: How to Reduce Frequency of Other Cores
  5. 4References

2 Enabling Thermal Shutdown Mandatory Step

This kicks in at the very end when temperature is close to max thresholds of the SoC.

This needs one time register programming to be done. Below is the complete programming sequence that can be done from the Linux user space in absence of thermal driver:

  1. WKUP_VTM_MISC_CTRL2[25-16] MAXT_OUTRG_ALERT_THR0 and WKUP_VTM_MISC_CTRL2[9-0] MAXT_OUTRG_ALERT_THR thresholds.
    Note: Setting 0x305 (decimal 773) that maps to 125°C as the TSHUT alert threshold and 0x2e6 (decimal 742) which maps to 120°C. This is the default recommendation for TSHUT. 
    devmem2 0x42050010 w 0x2e60305
    GUID-20210928-SS0I-FQPL-KHCR-VC64QTF7SF0F-low.png Figure 2-1 Temperature Translation Table

    The above table gives ADC code Vs Temperature in centigrade for few temperatures. In case other temperatures are needed, use Table 5-1897 equation to get the alert threshold values for a particular temperature.

    For more information, see the Temperature Translation table in the DRA829/TDA4VM/AM752x Technical Reference Manual

    Please use Silicon Revision 1.1 since Silicon Revision 1.0 has PVT sensor accuracy issue and the shutdown might happen at an offset of ± 20C.

  2. WKUP_VTM_TMPSENS_CTRL_j[11] MAXT_OUTRG_EN = 1.

    Enable the individual sensors maxtemp_alert bit (Note: bit 4 (CONT) and bit 6 (CLRZ) are already set so keeping them set):

    devmem2 0x42050300 w 0x850
devmem2 0x42050320 w 0x850
devmem2 0x42050340 w 0x850
devmem2 0x42050360 w 0x850
devmem2 0x42050380 w 0x850
  3. WKUP_VTM_MISC_CTRL[0] ANYMAXT_OUTRG_ALERT_EN to 1.

    The global max temp alert generation bit to 1.

    devmem2 0x4205000c w 0x1