- * Implement an open drain output using a GeneralIO, represented as a
- * GeneralIO. Requires an external pull-up for proper operation.
+ * Provide an open drain output as a GeneralIO using a GeneralIO.
+ *
+ * set() puts the pin in high impedance state by selecting the pin input mode.
+ * clr() sets the pin to sink current to ground by selecting the pin output
+ * mode, logic zero. Generally, an external pull-up resistor will be used with
+ * an open drain output.
+ *
+ * This pin can only be an open drain output and cannot be reconfigured.