CP3BT23_14 Datasheet, PDF (93/324 Pages) Texas Instruments – CP3BT23 Reprogrammable Connectivity Processor with Bluetooth and Dual CAN Interfaces

CP3BT23
www.ti.com
SNOSCX3A – JULY 2013 – REVISED JANUARY 2014
14.1.2 Port Direction Register (PxDIR)
The port direction register (PxDIR) determines whether each port pin is used for input or for output. A
clear bit in this register causes the corresponding pin to operate as an input, which puts the output buffer
in the high-impedance state. A set bit causes the pin to operate as an output, which enables the output
buffer.
A reset operation clears the port direction registers, which initializes the pins as inputs.
7
0
PxDIR
PxDIR
The PxDIR bits select the direction of the corresponding port pin.
0 – Input.
1 – Output.
14.1.3 Port Data Input Register (PxDIN)
The data input register (PxDIN) is a read-only register that returns the current state on each port pin. The
CPU can read this register at any time even when the pin is configured as an output.
7
0
PxDIN
PxDIN
The PxDIN bits indicate the state on the corresponding port pin.
0 – Pin is low.
1 – Pin is high.
14.1.4 Port Data Output Register (PxDOUT)
The data output register (PxDOUT) holds the data to be driven on output port pins. In this configuration,
writing to the register changes the output value. Reading the register returns the last value written to the
register.
A reset operation leaves the register contents unchanged. At power-up, the PxDOUT registers contain
unknown values.
7
0
PxDOUT
PxDOUT
The PxDOUT bits hold the data to be driven on pins configured as outputs in general-
purpose I/O mode.
0 – Drive the pin low.
1 – Drive the pin high.
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