MPC5606s clock configuration

mhogun · ‎01-20-2017

HI,

I am using one sample code for clock generation in mpc5606s controller.

the below line says is PLL0 is 64MHz ,but i am got confusion .kindly explain me how it is 64 MHz?

CGM.FMPLL[0].CR.R = 0x02400100; /* 8 MHz xtal: Set PLL0 to 64 MHz */

Also kindly give a idea about clock generation in mpc5606s controller.it will be more helpful.

Thank you in advance.

martin_kovar · ‎01-23-2017

Hello,

CGM.FMPLL[0].CR.R = 0x02400100 sets the following bits in CR register:

IDF = 0

ODF = 2

NDIV = 64

According the tables 8-22, 8-23 and 8-24 in reference manual:

Input divide ratio is 1 (IDF = 0)

Output divide ratio is 8 (ODF = 2)

Loo divide ratio is 64 (NDIV = 64)

Fsys = (input_clock * NDIV) / (IDF * ODF)

Fsys = (8MHz * 64) / (1 * 8)

Fsys = 64MHz

For more information, please read chapter Clock Description in MPC5606 Reference manual.

Regards,

Martin