This question is almost the same as this one. Section "2.3.4 VDDTn Filters" of "Hardware Design Guide for KeyStone I Devices" says about VDDTn supplies that "if none of the SerDes in a group are used then the VDDTn pins can be connected directly to the [1.5V] DVDD15 supply."
Yet:
- Section "6.1 Absolute Maximum Ratings" of TMS320C6678's datasheet says that VDDT1 and VDDT2's absolute maximum supply voltage is 1.3V.
- Section "7.3 Power Supplies" of TMS320C6678's datasheet says that VDDT1 and VDDT2 are "Filtered version of [1V] CVDD1. [...]"
- The answer in the thread mentioned before repeats what the Power Supplies section says about being filtered versions of CVDD1 but it does not directly say if the recommendation about using DVDD15 is right or not.
Is the recommendation to use DVDD15 for unused VDDTn supplies correct, despite the fact that DVDD15 is higher than the specified absolute maximum voltage and that if used those pins should be connected to 1V? If the datasheet is wrong, it seems like following its advice could damage the chip. If it is right, it is weird enough that I think it would be good to explain why a different voltage should be supplied when the features are unused.
