General Purpose Input Output, is a flexible parallel interface that allows a variety of custom connections. It also supports digital I/O Devices.
| Function Name | Description |
|---|---|
Pin Mode Functions |
A pin has three modes namely, Enabled, Disabled and Idle
as specified in the enumeration |
Pin Direction Functions |
Pins are used as inputs or outputs of binary signals. The Symbian platform GPIO class does not support bidirectional pins. However, some platforms allow pins to be in a quiescent state (also called floating or tri-state). |
Pin Bias Functions |
Provides programmable hardware to stabilize the state of a pin to its high or low state. |
Pin Idle Function |
Describes the state of the pin, whether it is in a third electrical state, different from High and Low. |
Interrupt Functions |
The treatment of interrupts is platform dependent. Typically, the hardware multiplexes all interrupts from a module into a hardware controller: in this case it is part of the GPIO implementation to demultiplex the requests. |
Wakeup Functions |
Wakeup requests will usually take place when the system is idling and clocks are switched off. |
Trigger Functions |
A trigger is the electrical waveform which signals an interrupt and sometimes a wakeup. Triggers are detected either by their level (high or low) or by their edge (rising, falling or both). When you associate an interrupt with a trigger you must specify the type (level or edge) and then the subtype. |
Debounce Functions |
Debouncing means filtering out distortions of the signal caused, for instance, by physical pressure on a key. |
Input and Output Functions |
Provides and verify that the pin is being used as a binary input or binary output. |
Note: All the above said functions are involved in implementing the Symbian platform
GPIO class.GPIO interface class.