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I/O Interface

The ULINKplus adapter has an 11-pin connector that can be used to monitor and control digital and analog signals on the target. The figure below provides schematics of this interface:

I/O test Schematic

The pin pitch is 2.54 mm.

I/O pin assignment and technical characteristics

The I/O pins on the connector may be used as follows:

Pin Name Function VTREG
  GND (1)
Ground for general purpose I/O pins 
N/A
+3.3V (2) Power for external circuits (switchable)
ULINK_3V3
0 Digital input/output
ULINK_IN / ULINK_OUT (bit 0)
1 Digital input/output
ULINK_IN / ULINK_OUT (bit 1)
2 Digital input/output ULINK_IN / ULINK_OUT (bit 2)
3 Digital input/output ULINK_IN / ULINK_OUT (bit 3)
4 Digital input/output;
Analog input
ULINK_IN / ULINK_OUT (bit 4);
ULINK_AIN4
5 Digital input/output;
Analog input
ULINK_IN / ULINK_OUT (bit 5);
ULINK_AIN5
6 Digital input/output;
Analog input
ULINK_IN / ULINK_OUT (bit 6);
ULINK_AIN6
7 Digital input/output;
Analog input/output
ULINK_IN / ULINK_OUT (bit 7);
ULINK_AIN7 / ULINK_AOUT7
8 Digital input/output ULINK_IN / ULINK_OUT (bit 8)

       (1) It is important to have the Test I/O GND connected to the target as the ULINKplus I/O, JTAG/SWD, and Power interfaces are fully isolated from each other and GND pins on this interfaces are not identical. 

       (2) The switchable +3.3V pin can deliver up to 10 mA current. 

The digital I/O pins have following characteristics:
  • 5V tolerance
  • Input Low: < 1.0V
  • Input High: >2.3V
  • Output Low: <0.4V @ 6mA
  • Output High: >2.9V @ -6mA
  • High-level short-circuit current (drive High; connected to GND): <10mA
  • Low-level short-circuit current (drive Low; connected to 3.3V): <10mA
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