When wake up from hibernate for a while one GPIO configured as output does not retain its state

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PeGu_352656
Level 2
Level 2

I use PSOC4100M. When wake up from hibernate for a while one GPIO configured as output goes low, which is not acceptable for my system. I tried to freeze it before go in hibernate but this does not help. While the MCU wakes up, the pin goes in tristate for a while again. Is there any way to keep its high logic during reset

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PriyadeepK_01
Employee
Employee
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I'm not sure if the device supports saving pin state during wake-up from hibernate, but one way  of achieving your requirement could be to configure the pin as open-drain drive low, and then connecting external pull-up to keep the pin state high.

Anonymous
Not applicable

The application note for low power modes doesn't have anything on GPIO saving state for hibernate, however, I know from my own testing that the deep-sleep power mode will save/use GPIO states. AN92584 - Designing for Low Power and Estimating Battery Life for BLE Applications

The default pin state is tristate on reset unfortunately; You could try wiring some components in the topdesign.cysch to see if that will force the pins to stay logic-high during reset (A digital output pin with the default state configured to high is really the only thing I can think of to try).

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