P9 / Pin 10 SYS_RESET changed to RESETSTATz (BBB -> BBAI64)

General Discussion
1

I was curious about the change in behavior for P9/pin 10 from SYS_RESET on beaglebone black and friends to RESETSTATz (MAIN domain warm reset status output). We have a provisioning use case where we require external programatic control over holding the board in reset. Is there an alternative path to SYS_RESET other than the user button? Is this an error or is there a stronger use case for exposing the MAIN domain reset status that I am missing?

2

Hi @mobileoverlord which RESET change you looking at? Rev A6 7/25/2013 or Rev C3 4/1/2021?

Regards,

3

I am specifically comparing BBB Rev C3 to BBAI64. However, It appears that the behavior of P9 / pin 10 (SYS_RESET) on the cape header was consistent throughout the series (beaglebone black, blue, green, ai) up until the AI-64. On the AI-64, the pin is an output and it seems is used to read the warm reset status. It can no longer be used to hold the system in reset.

4

@jkridner can you comment on this?

1 Like
5

It looks like it should go to RESET_REQZ (ball C28) for reset request
or PORZ (ball J24) for hard reset

page 133 of datasheet
image