RM57L843: cycles parameter of __delay_cycles()

Marcio Borges

Expert 1950 points

Part Number: RM57L843

Hi,

What is the clock to use to compute the "cycles" parameter of __delay_cycles()? PLL1 (300MHz), GCLK (300MHz), HCLK (150MHz)?

I am asking this question because the measurements I have done, do not match the GCLK clock (300MHz).

Best regards,

over 2 years ago

+1 jagadish gundavarapu over 2 years ago

TI__Guru 69811 points

Hi Marchio,

Marcio Borges said:
What is the clock to use to compute the "cycles" parameter of __delay_cycles()? PLL1 (300MHz), GCLK (300MHz), HCLK (150MHz)?

It should be the CPU clock (GCLK). I never tested practically but as per my knowledge from old threads it should be CPU clock that is GCLK.

Marcio Borges said:
I am asking this question because the measurements I have done, do not match the GCLK clock (300MHz).

Can you please reverify your measurements?

Thanks & regards,
Jagadish.

0 Marcio Borges over 2 years ago in reply to jagadish gundavarapu

Expert 1950 points

I did the measurements several times using a GPIO.

Maybe the error is because the cache is disabled and there is a delay to read the data from the internal flash. Also, the delay I want to count is too 100ms.

I´ll do more tests.

Thanks Jagadish.

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RM57L843: cycles parameter of __delay_cycles()