SCI Control Registers
1753
SPNU563A – March 2018
Copyright © 2018, Texas Instruments Incorporated
Serial Communication Interface (SCI) Module
30.7.12.3 Transmit Data Buffer Register (SCITD)
Data to be transmitted is written to the SCITD register.
and
illustrate this
register.
Figure 30-21. Transmit Data Buffer Register (SCITD) [offset = 38h]
31
16
Reserved
R-0
15
8
7
0
Reserved
TD
R-0
R/W-0
LEGEND: R/W = Read/Write; R = Read only; -
n
= value after reset
Table 30-20. Transmit Data Buffer Register (SCITD) Field Descriptions
Bit
Field
Value
Description
31-8
Reserved
0
Reads return 0. Writes have no effect.
7-0
TD
0-FFh
Transmit data. Data to be transmitted is written to the SCITD register. The transfer of data from
this register to the transmit shift register SCITXSHF sets the TXRDY flag (SCIFLR[8]), which
indicates that SCITD is ready to be loaded with another byte of data.
Note: If SET TX INT bit (SCISETINT[8] is set, this data transfer also causes an interrupt.
NOTE:
Data written to the SCITD register that is fewer than eight bits long must be right-justified,
but it does not need to be padded with leading zeros.
30.7.13 SCI Pin I/O Control Register 0 (SCIPIO0)
and
illustrate this register.
Figure 30-22. SCI Pin I/O Control Register 0 (SCIPIO0) [offset = 3Ch]
31
8
Reserved
R-0
7
3
2
1
0
Reserved
TX FUNC
RX FUNC
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 30-21. SCI Pin I/O Control Register 0 (SCIPIO0) Field Descriptions
Bit
Field
Value
Description
31-3
Reserved
0
Reads return 0. Writes have no effect.
2
TX FUNC
Transfer function. This bit defines the function of pin SCITX.
0
SCITX is a general-purpose digital I/O pin.
1
SCITX is the SCI transmit pin.
1
RX FUNC
Receive function. This bit defines the function of pin SCIRX.
0
SCIRX is a general-purpose digital I/O pin.
1
SCIRX is the SCI receive pin.
0
Reserved
0
Writes have no effect.