OPTIREG™ SBC TLE9274QXV33
LIN transceiver
9.2.3
LIN Receive-Only mode
In LIN Receive-Only mode (RX only), the driver stage is disabled but reception is still possible. This mode is
accessible by an SPI command and is available in SBC Normal and SBC Stop mode.
9.2.4
LIN Wake-Capable mode
This mode can be used in SBC Stop, Sleep, Restart and Normal mode by programming via SPI and it is used to
monitor bus activities. It is automatically accessed in SBC Fail-Safe mode. A wake up is detected, if a recessive
to dominant transition on the LIN bus is followed by a dominant level of longer than tWK,Bus, followed by a
dominant to recessive transition. The dominant to recessive transition will cause a wake up of the
LIN transceiver. A wake-up results different behavior of the SBC, as described in Table 14. As a signalization to
the microcontroller, the RXDLIN pin is set LOW and will stay LOW until the LIN transceiver is changed to any
other mode. After a wake-up event, the transceiver can be switched to LIN Normal mode for communication.
Table 14 Action due to a LIN bus wake-up
SBC mode
SBC mode after wake
Normal mode
Stop mode
VCC1
INT
RXDLIN
LOW
Normal mode
Stop mode
ON
LOW
LOW
HIGH
HIGH
HIGH
ON
LOW
Sleep mode
Restart mode
Fail-Safe mode
Restart mode
Restart mode
Restart mode
Ramping up
ON
LOW
LOW
Ramping up
LOW
Rearming the transceiver for wake capability
After a bus wake-up event, the transceiver is woken. However, the LIN1, LIN2, LIN3 and LIN4 transceiver
mode bits will still show wake capable (=‘01’) so that the RXDLIN signal will be pulled low. The Wake-Capable
mode of the LIN transceiver can be reenabled in one of two ways after a wake-up event:
•
•
•
By toggling the LIN transceiver mode, i.e. switched to LIN Normal mode, LIN Receive-Only mode or LIN Off,
before switching to LIN Wake-Capable mode again
Occurs automatically when the SBC changes to SBC Stop, SBC Sleep, or SBC Fail-Safe mode to ensure
wake-up capability
if the SBC is in SBC Stop mode, the LIN’s are rearmed automatically if the SBC is set again in SBC Stop mode
Wake-up in SBC Stop and SBC Normal mode
In SBC Stop mode, if a wake-up is detected, it is signaled by the INT output and in the WK_STAT_2 SPI register.
It is also signaled by RXDLIN put to LOW. The same applies for the SBC Normal mode. The microcontroller
should set the device to SBC Normal mode; there is no automatic transition to Normal mode.
For functional safety reasons, the watchdog will be automatically enabled in SBC Stop mode after a bus wake-
up event in case it was disabled before (if bit WD_EN_WK_BUS was configured to HIGH before).
Wake-up in SBC Sleep mode
Wake-up is possible via a LIN message (filter time t > tWK,Bus). The wake-up automatically transfers the SBC to
SBC Restart mode and from there to Normal mode. The corresponding RXDLIN pin in set to LOW. The
microcontroller is able to detect the low signal on RXDLIN and to read the wake source out of the WK_STAT_2
Datasheet
64
Rev.2.0
2022-05-06
INFINEON [ Infineon ]
