eTPU clock frequency

[jyothsnarajan]

Hi,

MPC5746R has eTPU2 and the highest clock frequency you can set it yup for is System_Clock/2, when you set the clockDivider to 2.

1.The processor reference manual addendum states one can set the clock divider to 1, eTPU simulator (Ashware eTPU DevTool) doesn't allow me to. 

Question: Can someone confirm if I can run the eTPU clock at the same speed as system clock?

2. The MPC574xR can run upto 200MHz, but the eTPU clock must only be configured for 133MHz or lower, per NXP recommendation. In the ETPU documentation, I find many references  to "System_Clock (SYS_CLK) .

Question: In my case where the processor speed is 200MHz but the eTPU_CLK is configured to operate at 133MHz, what should I use for the value of SYS-CLK,, in order to determine the values of the clock-divider and prescaler, for eTPU TCR1 and TCR2 configuration.

Appreciate your response. 

Thank you,

JoyR

[davidtosenovjan]

Hi

1) From eTPU point of view, eTPU Clock is system clock. On eTPU+ and eTPU2, eTPU channel logic may run at full eTPU clock. And from CPU point of view, SYS_CLK maximum limits are the same as eTPU clock. Pay attention to all screenshots below. So to summarize it, eTPU may run at system clock frequency.

2) Where this 133MHz NXP recommendation is taken from? I am not aware of it.