System Installation
ROBO-8771VG2 User’s Manual
3-8
Value of
Inversion Register
:
Only lower nibble is available for this function.
When set to a ‘1’, the incoming/outgoing port value is inverted.
When set to a ‘0’, the incoming/outgoing port value is the same as in Data Register.
Value of
I/O Selection Register
:
Only lower nibble is available for this function.
When set to a ‘1’, respective GPIO port is programmed as an input port.
When set to a ‘0’, respective GPIO port is programmed as an output port.
Value of
Output Data
/
Input Data
:
Only lower nibble is available for this function.
If a port is assigned to be an output port, then its respective bit can be read/written.
If a port is assigned to be an input port, then its respective bit can be read only.
Notes:
1) All the Buffered Digital Outputs are open-drain amplified form corresponding
GPIO ports.
2) Some other functions may occupy the high nibble of the registers. Altering any
content in high nibble will be undesired.
