SCI/LIN Control Registers
1698
SPNU563A – March 2018
Copyright © 2018, Texas Instruments Incorporated
Serial Communication Interface (SCI)/ Local Interconnect Network (LIN)
Module
29.7.13 SCI Data Buffers (SCIED, SCIRD, SCITD)
The SCI has three addressable registers in which transmit and receive data is stored. These three
registers are available in SCI mode only.
29.7.13.1 Receiver Emulation Data Buffer (SCIED)
The SCIED register is addressed at a location different from SCIRD, but is physically the same register.
and
illustrate this register.
Figure 29-40. Receiver Emulation Data Buffer (SCIED) (offset = 30h)
31
16
Reserved
R-0
15
8
7
0
Reserved
ED
R-0
R-0
LEGEND: R = Read only; -
n
= value after reset
Table 29-26. Receiver Emulation Data Buffer (SCIED) Field Descriptions
Bit
Field
Value
Description
31-8
Reserved
0
Reads return 0. Writes have no effect.
7-0
ED
0-FFh
Emulator data. This bit is effective in SCI-compatible mode only. Reading SCIED[7:0] does not
clear the RXRDY flag, unlike reading SCIRD. This register should be used only by an emulator
that must continually read the data buffer without affecting the RXRDY flag.
29.7.13.2 Receiver Data Buffer (SCIRD)
This register provides a location for the receiver data.
and
illustrate this register.
Figure 29-41. Receiver Data Buffer (SCIRD) (offset = 34h)
31
16
Reserved
R-0
15
8
7
0
Reserved
RD
R-0
R-0
LEGEND: R = Read only; -
n
= value after reset
Table 29-27. Receiver Data Buffer (SCIRD) Field Descriptions
Bit
Field
Value
Description
31-8
Reserved
0
Reads return 0. Writes have no effect.
7-0
RD
0-FFh
Receiver data. This bit is effective in SCI-compatible mode only. When a frame has been
completely received, the data in the frame is transferred from the receiver shift register SCIRXSHF
to this register. As this transfer occurs, the RXRDY flag is set and a receive interrupt is generated
if SET RX INT is set.
Note: When the data is read from SCIRD, the RXRDY flag is automatically cleared.
NOTE:
When the SCI receives data that is fewer than eight bits in length, it loads the data into this
register in a left justified format padded with trailing zeros. Therefore, your software should
perform a logical shift on the data by the correct number of positions to make it right justified.