SCI/LIN Control Registers
1670
SPNU563A – March 2018
Copyright © 2018, Texas Instruments Incorporated
Serial Communication Interface (SCI)/ Local Interconnect Network (LIN)
Module
Table 29-12. SCI Global Control Register 1 (SCIGCR1) Field Descriptions (continued)
Bit
Field
Value
Description
16
LOOP BACK
Loopback bit. This bit is effective in LIN and SCI modes. The self-checking option for the
SCI/LIN can be selected with this bit. If the LINITX and LINRX pins are configured with SCI/LIN
functionality, then the LINTX pin is internally connected to the LINRX pin. Externally, during loop
back operation, the LINTX pin outputs a high value and the LINRX pin is in a high-impedance
state. If this bit value is changed while the SCI/LIN is transmitting or receiving data, errors may
result.
0
Loop back mode is disabled.
1
Loop back mode is enabled.
15-14
Reserved
0
Reads return 0. Writes have no effect.
13
STOP EXT FRAME
Stop extended frame communication. This bit is effective in LIN mode only. This bit can be
written only during extended frame communication. When the extended frame communication is
stopped, this bit is cleared automatically.
0
This bit has no effect.
1
Extended frame communication will be stopped when current frame transmission/reception is
completed.
12
HGEN CTRL
HGEN control. This bit is effective in LIN mode only. This bit controls the type of mask filtering
comparison.
0
ID filtering using the ID-BYTE field in LIN Identification Register (LINID) occurs.
Mask of FFh in LIN Mask Register (LINMASK) register will result in no match.
1
ID filtering uses ID-SlaveTask BYTE (recommended).
Mask of FFh in LIN Mask Register (LINMASK) register will result in ALWAYS match.
Note: For software compatibility with future LIN modules the HGEN CTRL bit must be set
to 1, the RX ID MASK must be set to FFh and the TX ID MASK must be set to FFh.
11
CTYPE
Checksum type. This bit is effective in LIN mode only. This bit controls the type of checksum to
be used: classic or enhanced.
0
Classic checksum is used.
1
Enhanced checksum is used.
10
MBUF MODE
Multi-buffer mode. This bit is effective in LIN and SCI modes. This bit controls receive/transmit
buffer usage, that is, whether the RX/TX multi-buffers are used or a single register, RD0/TD0, is
used.
0
The multi-buffer mode is disabled.
1
The multi-buffer mode is enabled.
9
ADAPT
Adapt. This mode is effective in LIN mode only. This bit has an effect during the detection of the
synch field. Two LIN protocol bit rate modes could be enabled with this bit according to the
node capability file definition: automatic or select. The software and network configuration will
decide which of these two modes are enabled. When this bit is cleared, the LIN 2.0 protocol
fixed bit rate should be used. If the ADAPT bit is set, a SCI/LIN slave node detecting the baud
rate will compare it to the prescalers in BRS register and update it if they are different. The BRS
register will be updated with the new value. If this bit is not set there will be no adjustment to
the BRS register.
0
Automatic baud rate adjustment is disabled.
1
Automatic baud rate adjustment is enabled.
8
SLEEP
SCI sleep. This bit is effective in SCI mode only. In a multiprocessor configuration, this bit
controls the receive sleep function. Clearing this bit brings the SCI/LIN out of sleep mode.
0
Sleep mode is disabled.
1
Sleep mode is enabled.
Note: The receiver still operates when the SLEEP bit is set; however, RXRDY is updated
and SCIRD is loaded with new data only when an address frame is detected. The
remaining receiver status flags are updated and an error interrupt is requested if the
corresponding interrupt enable bit is set, regardless of the value of the SLEEP bit. In this
way, if an error is detected on the receive data line while the SCI is asleep, software can
promptly deal with the error condition.
Note: The SLEEP bit is not automatically cleared when an address byte is detected.
See
for more information on using the SLEEP bit for multiprocessor
communication.