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MPC5744P with 8MHz Oscillator , Aurora Interface

Question asked by Lars Krause on Nov 15, 2016
Latest reply on Nov 21, 2016 by Peter Vlna



I have 8MHz Extal instead of 40MHz, for MPC5744P cut2 rev3.


I use PLL0 to generate 160MHz (MOTC) and 40MHz (feeding PLL1).

In PLL1 I can generate out of the 40MHz the Sys_clk = 200MHz. This is working, since I can output the 200MHz on the oscilloscope.


But it seems there is some problem with the Aurora interface. I cannot connect to the target with 8MHz and the described settings.

Whereas, when using a 40MHz Xtal which feeds both PLL0 & PLL1 (not the cascaded PLL configuration) I have no problems. (The visualisation tool which establishes the connection to the target is Vector VX1132 and the VX1452 POD for HSSL- high speed serial link via Aurora).


I wonder whether I configured everything correctly for the cascaded PLL setting, I also did only find example source using 40MHz Xtal.


--> !! I also use the xls you provide for clocking, but e.g. there is not the hint like in ref-man:


NOTE: In cascaded PLL configuration (PLL0 driving the reference clock for PLL1) the external power
down signal for PLL1 must be removed only when PLL0 has locked, PLL0SR[LOCK] = 1.



.. do you have example source for cascaded pll ?