2.13 - DB15 [UE9 Datasheet]

The DB15 connector brings out 12 additional digital I/O.  It has the potential to be used as an expansion bus, where the 8 EIO are data lines and the 4 CIO are control lines.

In the Windows driver, the EIO are addressed as digital I/O bits 8 through 15, and the CIO are addressed as bits 16-19.

These 12 channels include an internal series resistor that provides overvoltage/short-circuit protection.  These series resistors also limit the ability of these lines to sink or source current.  Refer to the specifications in Appendix A.

All digital I/O on the UE9 have 3 possible states: input, output-high, or output-low.  Each bit of I/O can be configured individually.  When configured as an input, a bit has a ~100 kΩ pull-up resistor to 3.3 volts.  When configured as output-high, a bit is connected to the internal 3.3 volt supply (through a series resistor).  When configured as output-low, a bit is connected to GND (through a series resistor).

Table 2.13-1. DB15 Connector Pinouts

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