I asked a similar question on that thread about whether the PRUs exist at all on production BBAI64s since I was having a hard time finding anywhere, even in J721E documentation, where clock speed was discussed. But someone found a graphic where a clock line going to the PRU subsystem was marked (250MHz).
Having some documentation confirm a number, even if its just the default number was something. But I too would like to know if the mechanisms that clock the PRUs to 333MHz will do the same for the TDA4VM.
Although IIRC, the the AM243x that are capable of 333MHz only have the PRU_ICSS, not PRU_ICSSG subsystems.
Have you found some documentation for chips with PRU_ICSSGs that also say they are capable of 333MHz? If so, it might be interesting to see what registers and values you use to set that speed and then see what happens when you do the same on a BBAI64.
But as it relates to the TDA4VM, it really bothers me that TI pulled support for the PRUs and doesn’t even claim their presence yet the BB community is claiming them and relying on their presence. Not to take anything away from the other aspects of the TDA4VM, but the PRUs are what really add value to the platform IMO…and TI has abandoned them for TDA4VM.