With MPC5644A, we are using both the eMIOS and the eTPU. The EMIOS_MCR[GTBE] enables the eMIOS A/B counters to start. The ETPU_MCR[GTBE] enables eTPU engines to start executing code. However, are these 2 bits the same?
In MPC5644A RM Rev 6, §188.8.131.52 "GTBE – Global time base enable" explains that in the eTPU, there are 2 GTBE signals: etpu_gtbe_out and etpu_gtbe_in. The etpu_gtbe_out might be OR'ed with another signal at MCU level before being sent back as etpu_gtbe_in. I guess it is OR'ed with EMIOS_MCR[GTBE]. However, this information is missing from the reference manual.