Rabbit BL2600, User Manual

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24 SBC BL2600
When you use the software
digIn
function call to read the configurable I/O, DIO00–
DIO15 are considered to be digital input channels 00–15. Note that the
digIn
function
call can also read these channels if they are set to be sinking digital outputs.
Table 7 lists the banks of configured digital inputs and summarizes the jumper settings.
As for the nonconfigurable digital inputs, the actual switching threshold is approximately
1.40 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.
NOTE: If the inputs are pulled up to +K or to DCIN, the voltage range over which
the digital inputs are protected changes to +K (or DCIN) – 36 V to +36 V.
When set as a sinking digital output, a configurable I/O channel can sink up to 200 mA at
up to 40 V. When you use the software
digOutConfig
function call to set the configu-
rable I/O, DIO00–DIO15 are considered to be digital output channels 00–15. The output
can be set up either as a sinking output or it can be put in a high-impedance tristate.
Table 7. Banks of BL2600 Configured Digital Inputs
Digital Inputs Header Pins Jumpered Pulled Up/Pulled Down
DIO00–DIO07 JP1 1–2 Inputs pulled up to +5 V
DIO08–DIO15 JP2 3–4 Inputs pulled up to DCIN
5–6 Inputs pulled up to +K
7–8 Inputs pulled down to GND
When a configurable I/O is configured
as a sinking output, be sure to connect
an external voltage source up to 36 V
DC K and GND on header
J1/J3, and set the pullup jumper on the
corresponding JP1/JP2 header to +K.
Figure 13. Load and +K Power Supply
Connections for Sinking Digital Output
DIO00–DIO15
LOAD
+K
GND