System Installation
ROBO-8771VG2 User’s Manual
3-6
3.8 GPIO
The ROBO-8771VG2 provides 8 GPIO ports that can be individually configured to
perform a simple basic I/O function. Users can configure each individual port to
become an input or output port by programming register bit of I/O Selection. To
invert port value, the setting of Inversion Register has to be made. Port values can be
set to read or write through Data Register.
3.8.1 Pin
assignment
J23: GPIO Connector
J23
H5x2
1
3
5
7
2
4
6
8
9
10
PIN No.
Signal Description
PIN No.
Signal Description
1
GPIO Port0
2
GPIO Port4
3
GPIO Port1
4
GPIO Port5
5
GPIO Port2
6
GPIO Port6
7
GPIO Port3
8
GPIO Port7
9 Ground
10 +5V
3.8.2
PEB-8771VG2 GPIO Programming Guide
Additionally, 8-extra Digital Output ports inversely amplified signals from GPIO
ports. There are open-drain buffers, which can offer greater driving capacity up to
100mA.
There are two PNP I/O port addresses that can be used to configure GPIO ports,
1) 0x2E -
EFER
(Extended Function Enable Register, for entering Extended Function
Mode)
-
EFIR
(Extended Function Index Register, for identifying CR index number)
2) 0x2F -
EFDR
(Extended Function Data Register, for accessing desired CR)
