Unused I/O Pins - Texas Instruments SimpleLink CC2620 Technical Reference Manual

Unused I/O Pins

11.6 Unused I/O Pins
By default, the I/O driver (output) and input buffer (input) are disabled at power on or reset, and thus the
I/O pin can safely be left unconnected (floating).
If the I/O pin is tri-stated and connected to a node with a different voltage potential; there might be a small
leakage current going through the pin. The same applies to an I/O pin configured as input, where the pin
is connected to a voltage source (for example VDD / 2). The input is then an undefined value of either
0 or 1.
11.7 GPIO
The MCU GPIO is a general-purpose input/output that drives a number of physical I/O pads. GPIO
supports up to 31 programmable I/O pins. These pins are configured by the IOC module. To modify a
single GPIO output value, use the GPIO:DOUTn registers (see
up DIO1 as a GPIO output and toggle the bit, use the following procedure.
1. Map DIO1 as a GPIO output by setting the IOC:IOCFG1.PORT_ID register to 0 (GPIO PORDTID).
2. Ensure DIO1 is set as output by clearing the IOC:IOCFG1.IE bit. More port configurations can also be
set in the IOC:IOCFG1 register; see
3. Set the data output enable bit for DIO1 in GPIO:DOE31_0.DIO1 by issuing a read-modify-write
operation.
4. Toggle the DIO1 output by issuing an XOR operation on the GPIO:DOUT3_0:DIO1 bit with 0x100.
5. Call the following driver library functions:
IOCPinTypeGpioOutput(0x1);
GPIOPinToggle(0x1);
876
I/O Control
Section 11.10.2 Pin Configuration, for more details.
Copyright © 2015, Texas Instruments Incorporated
Section 11.11.2, GPIO Registers). To set
SWCU117C – February 2015 – Revised September 2015
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