I set one of the GPIO ports (STR912FAW44 ARM microcontroller) to output mode and open collector type. Then I connect pull-up resistors to all pins on the port.
When I write a one to a pin, I detect a high (through an oscilloscope.) And when I write a zero, it goes low. All seems to be perfect.
When I write a one and shorted the pin, I see a low as expected. However, when I read the pin again it remains as one. In the documentation, it says when in output mode, the microcontroller will read the state on the pin itself and not the internal state. Am I missing something here?
Can some shed some light, please?