topic Re: How to sync two IMXRT ? Clock/Counter ? in Rapid IoT

How to sync two IMXRT ? Clock/Counter ?

Tomlogan — Wed, 12 Oct 2022 12:08:07 GMT

Hi,

I would like to synchronize two IMXRT.

I was wondering what could be use for that and what performances could I get ? and stability ?

I was thinking to use two GPIO and pulse to sync both and calculate the propagation delay on init phase.

Re: How to sync two IMXRT ? Clock/Counter ?

jingpan — Thu, 13 Oct 2022 07:43:46 GMT

Hi @Tomlogan ,

What do you mean of synchronize?

Regards,

Jing

Re: How to sync two IMXRT ? Clock/Counter ?

Tomlogan — Thu, 13 Oct 2022 08:10:09 GMT

Hi @jingpan ,

What I mean by synchronize is that both IMXRT can perform actions simultaneously (+/- threshold), I have seen some topic about distributed clock but the hardware is already fixed and doesn't provide one.

How can I insure that both IMXRT make the action at the same time ?

Re: How to sync two IMXRT ? Clock/Counter ?

jingpan — Thu, 13 Oct 2022 08:29:51 GMT

Hi @Tomlogan ,

Sounds very hard. We haven't such experience. Maybe you can have an external clock source, connect to both of the XTALI. After initialization, let them wait for a single start signal. But I have to say, the difference is unpredictable. They are 600Mhz devices.

You can wait for S32K3. It has two cores and can step lock.

Regards,

Jing

Re: How to sync two IMXRT ? Clock/Counter ?

Tomlogan — Thu, 13 Oct 2022 09:24:12 GMT

Thanks for the reply.

You mentionned a solution based on clock and adding hardware.

What could I do with the current one, IMXRT family and GPIO to insure this synchronization ? On a software level maybe.

I should say that the needed performance is not evaluated right now. It's just a POC to etablish a synchronization between IMXRT chips.

Re: How to sync two IMXRT ? Clock/Counter ?

jingpan — Fri, 14 Oct 2022 02:37:17 GMT

Hi,

What's the purpose of synchronize? What level can be acceptable?

Regards,

Jing

Re: How to sync two IMXRT ? Clock/Counter ?

Tomlogan — Fri, 14 Oct 2022 08:08:17 GMT

The purpose of synchronize is to send a data from one to another IMXRT on the same time reference and avoid outdated data. It shoud also help to perform synchronous actions.

About the level, as low as possible, yesterday I try to use the GPIO as fast as possible with a toggle but there is some jitter. I try to run my sample code with Release toolchain with a slight improve.

Re: How to sync two IMXRT ? Clock/Counter ?

jingpan — Mon, 17 Oct 2022 08:54:16 GMT

Hi,

I can't find out other better solution.

Regards,

Jing