SPRUIW9C October 2021 – March 2024 TMS320F280033 , TMS320F280034 , TMS320F280034-Q1 , TMS320F280036-Q1 , TMS320F280036C-Q1 , TMS320F280037 , TMS320F280037-Q1 , TMS320F280037C , TMS320F280037C-Q1 , TMS320F280038-Q1 , TMS320F280038C-Q1 , TMS320F280039 , TMS320F280039-Q1 , TMS320F280039C , TMS320F280039C-Q1
If the application requires the PLL clock to be bypassed from the system, then the application needs to configure SYSPLLCTL1.PLLCLKEN = 0. The bypass can take up to 60 CPU clock cycles before the bypass is effective. In the meantime, if PLLSYSCLKDIV is reduced to a lower value (for example from /2 to /1 or /4 to /2) the device can be clocked above the maximum rated frequency and can lead to unpredictable device behavior. Hence, a delay of 60 CPU clock cycles is required after bypassing the PLL from enable state, that is, going from PLLCLKEN = 1 to PLLCLKEN = 0.