Well I was able to force the pin (P0^4) to either Logic High or Logic Low as per the knowledge base articles, thanks for the ideas.

Further to my story I am using the port and another "normal" port (P3^3) for direction control on a L298 H Bridge motor driver.

Then I have a 3rd PWM pin (P0^5) for speed control.

The P3^3 port swings between 0 - 3V3 for direction 1. the P0^4 (PWM 0 or 100%) that is forced high or low, is only able to swing between 0 -2V (not enough to effectively change the direction)

When it is not connected to the H Bridge driver, it swings normally.

If I use another spare port (P1^0) on the uC SILABS 8051C047 I can drive the port, and control the motor in either direction.

All ports discussed here are configured as push-pull. I would really like to use P0^4 as it saves hacking the boards and putting little green wires on it.

Any thoughts.

Regards

Marshall