RabbitCore RCM3315, User Manual, Page: 94 / 160

88 RabbitCore RCM3305/RCM3315
B.4.2 Digital I/O
B.4.2.1 Digital Inputs
The Prototyping Board has four digital inputs, IN0–IN3, each of which is protected over a
range of –36 V to +36 V. The inputs are pulled up to +3.3 V as shown in Figure B-5.
Figure B-5. Prototyping Board Digital Inputs
The four quadrature decoder inputs on screw-terminal header J5 may be used as inputs
IN4–IN7. To use the PF0 signal from the Rabbit microprocessor, which goes to QD1B,
remember to reconfigure the jumper on header JP3 to jumper pins 1–2.
The actual switching threshold is between 0.9 V and 2.3 V. Anything below this value is a
logic 0, and anything above is a logic 1
.
The digital inputs are each fully protected over a range of -36 V to +36 V, and can handle
short spikes of ±40 V.
JP6
22 k W
27 k W
+3.3 V
GND
®