# Reboot command

**URL:** <https://forums.sifive.com/t/reboot-command/4721>\
**Category:** HiFive Unmatched\
**Created:** [May 28, 2021, 5:02pm UTC](https://forums.sifive.com/t/reboot-command/4721 "2021-05-28T17:02:42Z")\
**Posts on this page:** 1\
**Showing post:** 28

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**Author:** ![alexghiti](https://avatars.discourse-cdn.com/v4/letter/a/b3f665/32.png) [@alexghiti](https://forums.sifive.com/u/alexghiti)\
**Post date:** [September 17, 2021, 5:29am UTC](https://forums.sifive.com/t/reboot-command/4721/28 "2021-09-17T05:29:25Z")

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Hi guys,

I ported your sequence to a u-boot driver and noticed that, although it works reliably, turning off the board within 16seconds after this sequence is not possible since the board would restart. Weirdly, I did not have this issue when launching the sequence from the u-boot shell: by adding a few sleeps between the register writes in my u-boot driver, it finally worked. It seems the behavior I’m facing is described in the thread shared before ([Power Management ICs (PMICs) | Dialog](https://www.dialog-semiconductor.com/products/pmics?post_id=10052#tab-support_tab_content)) and I don’t quite understand why it does not happen all the time.

Anyway, as the “sleeps” solution did not suit me, I digged the datasheet and found a shorter sequence that does not give rise to the issue:

i2c dev 0;  
i2c mw 0x58 0x13 0x4; // Set the WAKE\_UP bit to CONTROL\_F  
i2c mw 0x58 0xe 0x68; // Powerdown

It works reliably for me, if you have a chance to test this, any feedback is welcome.

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