Hi @User , you might be able to shed light on this. Comments in gpio_control_block.v suggest oeb=0 disables the output, but other conversations in slack state that user_gpio_oeb=0 is required to enable the output driver. Can you confirm that user_gpio_oeb=0 is needed to enable the output (when configured for user IO)?

I regret having over-complicated the GPIO controls. . . There is somewhat different behavior depending on whether the GPIO is configured for control by the management SoC or by the user project. For the user project, if you set the

oeb

configuration register bit to 0, then you turn off the input buffer and the pin can only be used for output. You would normally want to set the

oeb

bit to 1, in which case the input buffer is turned on, and the state of the output buffer is determined by the

user_gpio_oeb

signal.

We have pins input-only and output-only. For the outputs, is that to say it is determined only by the oeb setting in the config register: i.e., user_gpio_oeb is don’t care?

No, it's the

oeb

configuration bit that is don't care. The output state is determined solely by the

user_gpio_oeb

signal.

Got it. We are building boards and want to predict chance to test it — success. Is user_gpio_oeb=0 the correct value to set the output active (driving out)?

@User yes