Hi,
The only info about the STAC bus is given in the RM.
The STAC bus allows an eTPU to export its timebase (TCR1/TCR2) to another eTPU as well as to other peripherals such as the eMIOS.
As you mentioned the STAC is described in the chapter 43.14.6.3. See also chapter 43.7.4 and 43.7.8; the eTPUx REDCR ((eTPU_TBR_STAC_ENGx registers) have to be properly set to configure the eTPU STAC bus operation as a STAC Server/Client module. The Server ID assignment is showed in chapter 43.1.7 STAC bus.
If the STAC-bus Export/Import feature is used, the clock ratio of eTPU : eMIOS should be 1:1 or 2:1
Chapter 42.6.3 STAC Bus Client submodule describes STAC bus usage within an eMIOS module. As there are 2 engines (2 eTPU modules) you have 4 fixed time slots.
BR, Petr
