IMX8M reset implementation

[vadimaleynikov]

The i.MX 8MDQLQ Hardware Developer’s Guide in Table 7 recommends that the reset button should be connected to the PMIC enable pin. In this case, the iMX8M reset is impelmented by swithching off all the IMX8M power (except probably SNVS). 

What is the reason of a such drastic reset way?

Whether a less radical method of resetting the IMX8M exist (which doesn't require switching power off)?

Best regards,
Vadim Aleynikov

[igorpadykov · Accepted solution]

Hi Vadim

such reset solution is similar one used on i.MX6Q Sabre SD board designs,

please check p.21 spf-27392 "PWRON" signal.

Schematics (1)
i.MX6_SABRE_SDP_DESIGNFILES
http://www.nxp.com/products/software-and-tools/hardware-development-tools/sabre-development-system/s...

or ENGR00338067 mentioned in AN5161 p.24

https://www.nxp.com/docs/en/application-note/AN5161.pdf 

Swithching off all the IMX power is fool proof universal reset solution, probably one can use other solutions

but this require detailed schematic analysis for implications when some components remain

in non-reset state. There is no usiversal solution and each case should be separately considered.

Best regards
igor
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[vadimaleynikov]

Thank you, Igor.

Vadim