SPC560D clock source

Patriks · ‎2014-10-08

Posted on October 08, 2014 at 15:56

Hello,

If I am using the command ''

asm volatile (''nop'');

'', how long should the controller need to execute this command?

I ask this question because I have tried to use it as an indicator for the system clock. Currently, I am using the SPC560D discovery board and my clock source is the FMPLL, configured for a clock of 48MHz. The SPC5-UDESTK and UDE Visual Platform shows me an execution time of 208ns for this command. This seems too much for me for a system clock of 48Mhz. Shouldn´t it be around 10ns?

To do another test, I used the internal 16Mhz RC as system clock. The strange thing is, that the execution time for this command is exactly the same.

Best regards,

Patrik

Erwan YVIN · ‎2014-11-14

Posted on November 14, 2014 at 16:08

Hello Patrik ,

i am not sure that it could be a relevant information by using :

SPC5-UDESTK is USB/JTAG token.

to do this ..often , i prefer use a ETM. (not the same price)

Best Regards

Erwan