Shenzhen Coban Electronics Co. Ltd. CB900 用户手册
Figure 15: Example of earphone implementation
4.11. General Purposes Input / Output ports
Pin Description and Electrical Characteristics
4.12. Keyboard Interface
The 10-pin keyboard interface includes 4 row inputs and 4 column outputs. The 8 lines can
be used as general purpose inputs and outputs. Please contact COBAN directly for more
information on the extended customization to this interface.
Pin Description and Electrical Characteristics
Pin
Signal Name
Parameters
Min
Type
Max
Unit
4
9
21
48
49
53
GPIO79
GPIO81
GPIO18
GPIO45
GPIO61
GPIO16
High level input voltage, VIH
2.5
3
V
Low level input voltage, VIL
0
0.3
V
High level output voltage, VOH
2.6
2.8
2.85
V
Low level output voltage, VOL
-
-
0.45
V
Pin
Signal Name
Parameters
Min
Type
Max
Unit
54
55
56
KCOL3
KCOL0
KCOL2
High level input voltage, VIH
2.5
3
V
Low level input voltage, VIL
0
0.3
V