SCI/LIN Control Registers
1277
SPNU503C – March 2018
Copyright © 2018, Texas Instruments Incorporated
Serial Communication Interface (SCI)/ Local Interconnect Network (LIN)
Module
Table 25-11. SCI Global Control Register 1 (SCIGCR1) Field Descriptions (continued)
Bit
Field
Value
Description
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 (see
) 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.
7
SWnRST
Software reset (active low). This bit is effective in LIN and SCI modes.
0
The SCI/LIN is in its reset state; no data will be transmitted or received. Writing a 0 to this bit
initializes the SCI/LIN state machines and operating flags as defined in
and
. All affected logic is held in the reset state until a 1 is written to this bit.
1
The SCI/LIN is in its ready state; transmission and reception can be done. After this bit is set to
1, the configuration of the module should not change.
Note: The SCI/LIN should only be configured while SWnRST = 0.
6
LIN MODE
LIN mode. This bit is effective in LIN and SCI mode. This bit controls the module mode of
operation.
0
LIN mode is disabled; SCI mode is enabled.
1
LIN mode is enabled; SCI mode is disabled.
5
CLOCK
SCI internal clock enable. The CLOCK bit determines the source of the module clock on the
SCICLK pin. It also determines whether a LIN node is a slave or master.
SCI mode
0
The external SCICLK is the clock source.
Note: If an external clock is selected, then the internal baud rate generator and baud rate
registers are bypassed. The maximum frequency allowed for an externally sourced SCI
clock is VCLK/16.
1
The internal SCICLK is the clock source.
LIN mode
0
The node is in slave mode.
1
The node is in master mode.
4
STOP
SCI number of stop bits per frame. This bit is effective in SCI mode only.
0
One stop bit is used.
1
Two stop bits are used.
Note: The receiver checks for only one stop bit. However in idle-line mode, the receiver
waits until the end of the second stop bit (if STOP = 1) to begin checking for an idle
period
.
3
PARITY
SCI parity odd/even selection. This bit is effective in SCI mode only. If the PARITY ENA bit is
set, PARITY designates odd or even parity.
0
Odd parity is used.
1
Even parity is used.
The parity bit is calculated based on the data bits in each frame and the address bit (in
address-bit mode). The start and stop fields in the frame are not included in the parity
calculation.
For odd parity, the SCI transmits and expects to receive a value in the parity bit that
makes odd the total number of bits in the frame with the value of 1.
For even parity, the SCI transmits and expects to receive a value in the parity bit that
makes even the total number of bits in the frame with the value of 1.