Changing System Clock Frequency can not speed up processing speed when using MPC5744P

[bruceye]

Hi :

I have a problem to speed up the calculation of the MPC5744P by changing the system clock frequency.

First of all, 16 MHz IRCOSC was used as the system clock ( MC_ME.RUN0_MC.B.SYSCLK = 0;)and I tested  the time for MPC5744P to process a formula, it takes around 100us (Testing by PIT) .Then I used the primary PLL (PHI) as the source of system clock ( MC_ME.RUN0_MC.B.SYSCLK = 2), so the system clock frequency is supposed to be 160MHZ. But the processing time stayed unchanged .

Could you give me some advice on why I cannot speed up processing speed by changing  system clock frequency ?

Thanks

Bruce

[davidtosenovjan]

Hi, it is not supposed to be changed. PIT uses IRC as clock source:

[bruceye]

Hi David：

Thank you for your reply.Probably because I did not express my problem clearly that you misunderstood what I mean .

My problem is I can not speed up the microcontroller's speed by changing the clock source of the system clock(from 16Mhz to 160Mhz).Using PIT was just to detect how long it takes for a microcontroller to run a program.The result is that  I can not speed up processing speed by changing  system clock frequency.

So could you please give me some advice again ?

Thank you

Bruce

[xiaopi]

hi,i have the same problem just like you faced.coule you give you email or wechat,i really want to know how to speed up the microcontroller's speed.

my email is 382215239@qq.com,you can contact me also.

[davidtosenovjan]

I see.

Please pay attention to following example code, functions SysClk_Init and PeriClkGen_init:

Example MPC5744P PinToggleStationery S32DS 

Hope it helps.