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Merged
merged 1 commit into from
Oct 20, 2025
Merged

Enable NXP LPUART pin internal pullup resistor #96998

merged 1 commit into from
Oct 20, 2025

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@ZhaoxiangJin
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This commit enables MCXN236, MCXN947 LPUART pin internal pullup resistor. For MCXN947 and MCXN236, during LPUAR initialization, the RX pin is pulled down internally and STAT[RAF] is set to one. In this state, attempting to enter low power mode will trigger LPACK reset and therefore cannot truly enter low power mode. The correct setting should be to enable LPUART pin internal pullup resistor.

@ZhaoxiangJin ZhaoxiangJin marked this pull request as ready for review October 4, 2025 02:07
@ZhaoxiangJin
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I can reproduce the twister failure in zephyr and mcuboot latest main, it seems several NXP platforms have recently been broken in main. cc @hakehuang

@hakehuang
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I can reproduce the twister failure in zephyr and mcuboot latest main, it seems several NXP platforms have recently been broken in main. cc @hakehuang

#97020 @ZhaoxiangJin Thanks for notifying.

@JarmouniA JarmouniA mentioned this pull request Oct 7, 2025
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@ZhaoxiangJin ZhaoxiangJin force-pushed the enable-nxp-lpuart-pin-internal-pullup-resistor branch from ac83e81 to 778b5dc Compare October 8, 2025 04:41
@ZhaoxiangJin
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I can reproduce the twister failure in zephyr and mcuboot latest main, it seems several NXP platforms have recently been broken in main. cc @hakehuang

#97020 @ZhaoxiangJin Thanks for notifying.

Hello @hakehuang, I see #97020 is closed, I tried to rebase to the latest main, but the CI still get failures, could you please help check again? Thanks!

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Hello @hakehuang, I see #97020 is closed, I tried to rebase to the latest main, but the CI still get failures, could you please help check again? Thanks!

there is another issue reported #97021

@ZhaoxiangJin ZhaoxiangJin mentioned this pull request Oct 10, 2025
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@dleach02 dleach02 added the Trivial Changes that can be reviewed by anyone, i.e. doc changes, minor build system tweaks, etc. label Oct 13, 2025
@ZhaoxiangJin ZhaoxiangJin force-pushed the enable-nxp-lpuart-pin-internal-pullup-resistor branch from 778b5dc to bbccb5d Compare October 15, 2025 01:29
@ZhaoxiangJin
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Update:
Just rebased to the top main to fix the CI issue, no code change

@ZhaoxiangJin
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CI has been broken once again. ++@hakehuang for checking.

@hakehuang
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CI has been broken once again. ++@hakehuang for checking.

Thanks notifying, checking

@hakehuang
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hakehuang commented Oct 15, 2025 •
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#97021 is not resolved yet.
#97581 #97583 newly introduced

@ZhaoxiangJin ZhaoxiangJin mentioned this pull request Oct 16, 2025
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@ZhaoxiangJin ZhaoxiangJin force-pushed the enable-nxp-lpuart-pin-internal-pullup-resistor branch from bbccb5d to 66e26cf Compare October 17, 2025 00:45
@ZhaoxiangJin
boards/nxp: mcxn: Enable LPUART pin internal pullup resistor
c1fdcd3 
This commit enables MCXN236, MCXN947 LPUART pin internal
pullup resistor. For MCXN947 and MCXN236, during LPUAR
initialization, the RX pin is pulled down internally
and STAT[RAF] is set to one. In this state, attempting
to enter low power mode will trigger LPACK reset and
therefore cannot truly enter low power mode. The correct
setting should be to enable LPUART pin internal pullup
resistor.

Signed-off-by: Zhaoxiang Jin <[email protected]>
@ZhaoxiangJin ZhaoxiangJin force-pushed the enable-nxp-lpuart-pin-internal-pullup-resistor branch from 66e26cf to c1fdcd3 Compare October 20, 2025 15:34
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Quality Gate Passed Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud

@cfriedt cfriedt merged commit 43c223e into zephyrproject-rtos:main Oct 20, 2025
23 checks passed
@ZhaoxiangJin ZhaoxiangJin deleted the enable-nxp-lpuart-pin-internal-pullup-resistor branch October 21, 2025 06:15
@dleach02 dleach02 mentioned this pull request Oct 21, 2025
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@mmahadevan108 mmahadevan108 mmahadevan108 approved these changes

@dleach02 dleach02 dleach02 approved these changes

@butok butok Awaiting requested review from butok

@decsny decsny Awaiting requested review from decsny

@DerekSnell DerekSnell Awaiting requested review from DerekSnell

@EmilioCBen EmilioCBen Awaiting requested review from EmilioCBen

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@mmahadevan108 mmahadevan108

@dleach02 dleach02

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@ZhaoxiangJin @hakehuang @mmahadevan108 @dleach02 @cfriedt @zephyrbot