Relying on microcontroller pin protection diodes?

I want to drive a 270Ω coil with a bipolar 1.5V square wave from a microcontroller (PIC16F1847) running on 5V. First thought was an h-bridge but that seems over the top. Second thought was simply the coil in series with a 620Ω resistor between two of the uC pins but this would rely on the pin protection diodes to catch inductive spikes. The spec from the datasheet (I think) sets a maximum current at 20mA and this would be only 5.5mA.

Is this a good idea, or dangerous?

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Relying on microcontroller pin protection diodes?