SCI Control Registers
1754
SPNU563A – March 2018
Copyright © 2018, Texas Instruments Incorporated
Serial Communication Interface (SCI) Module
30.7.14 SCI Pin I/O Control Register 1 (SCIPIO1)
and
illustrate this register.
Figure 30-23. SCI Pin I/O Control Register 1 (SCIPIO1) [offset = 40h]
31
8
Reserved
R-0
7
3
2
1
0
Reserved
TX DIR
RX DIR
Reserved
R-0
R/W-0
R/W-0
R/W-0
LEGEND: R/W = Read/Write; R = Read only; -
n
= value after reset
Table 30-22. SCI Pin I/O Control Register 1 (SCIPIO1) Field Descriptions
Bit
Field
Value
Description
31-3
Reserved
0
Reads return 0. Writes have no effect.
2
TX DIR
Transmit pin direction. This bit determines the data direction on the SCITX pin if it is configured with
general-purpose I/O functionality (TX FUNC = 0). See
for the SCITX pin control with this bit
and others.
0
SCITX is a general-purpose input pin.
1
SCITX is a general-purpose output pin.
1
RX DIR
Receive pin direction. This bit determines the data direction on the SCIRX pin if it is configured with
general-purpose I/O functionality (RX FUNC = 0). See
for the SCIRX pin control with this
bit and others.
0
SCIRX is a general-purpose input pin.
1
SCIRX is a general-purpose output pin.
0
Reserved
0
Writes have no effect.
(1)
TX IN is a read-only bit. Its value always reflects the level of the SCITX pin.
Table 30-23. SCITX Pin Control
Function
TX IN
(1)
TX OUT
TX FUNC
TX DIR
SCITX
X
X
1
X
General-purpose input
X
X
0
0
General-purpose output, high
X
1
0
1
General-purpose output, low
X
0
0
1
(1)
RX IN is a read-only bit. Its value always reflects the level of the SCIRX pin.
Table 30-24. SCIRX Pin Control
Function
RX IN
(1)
RX OUT
RX FUNC
RX DIR
SCIRX
X
X
1
X
General-purpose input
X
X
0
0
General-purpose output, high
X
1
0
1
General-purpose output, low
X
0
0
1