i.MX ProcessorsのトピックRe: Capture GPT value based on RTC event

Capture GPT value based on RTC event

thomaskofoedhan — Fri, 03 Mar 2017 13:35:52 GMT

Can anyone tell me if it's possible to source a general purpose timer from the CCM_CLK2 pin and capture it's value based on an events from the RTC block?

The reason I ask is that I want to synchronize an external oscillator connected to CCM_CLK2 pin with my 32,768kHz clock on the RTC_XTALI pin.

Re: Capture GPT value based on RTC event

igorpadykov — Fri, 03 Mar 2017 23:15:42 GMT

Hi Thomas

Seems this is possible with CCM_EXT_CLK1, please check Table 5-10. CCM External Signals,

sect.8.1.1.1 Muxing Options, GPT1_CLK_ROOT.

http://cache.nxp.com/files/32bit/doc/ref_manual/IMX7DRM.pdf

RTC interrupt event (example can be found in imx-test package, folder mxc_rtc)

can be used by procesor to read gpt value

www.nxp.com/lgfiles/NMG/MAD/YOCTO/imx-test-5.7.tar.gz

Best regards
igor
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Re: Capture GPT value based on RTC event

thomaskofoedhan — Fri, 10 Mar 2017 16:02:03 GMT

Hi Igor,

I'm a bit confused about your comment about the CLK2 being an output, but I think I understand where it comes from. I have also seen it somewhere in the datasheet or reference manual but can't find it again. But if you read chapter 5.1.3.3-4 of the reference manual it is explicitly mentioned as an input.

Thomas

Re: Capture GPT value based on RTC event

igorpadykov — Fri, 10 Mar 2017 23:21:05 GMT

Hi Thomas

sorry you are right CLK2 is input, Table 5-10 has misprint and document

will be updated.

Best regards
igor