Data Sheet
83
Rev. 1.00
2017-07-31
TLE9262BQXV33
LIN Transceiver
11.2.4
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 t
WK,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 in a different behavior of the SBC, as described in below
Table 18
. As a
signalization to the microcontroller, the RXD_LIN 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.
Rearming the transceiver for wake capability
After a BUS wake-up event, the transceiver is woken. However, the
LIN1
transceiver mode bits will still show
wake capable (=‘01’) so that the RXD signal will be pulled low. There are two possibilities how the LIN
transceiver’s wake capable mode is enabled again after a wake event:
•
The LIN transceiver mode must be toggled, i.e. switched to LIN Normal Mode, LIN Receive Only Mode or LIN
Off, before switching to LIN Wake Capable Mode again.
•
Rearming is done automatically when the SBC is changed to SBC Stop, SBC Sleep, or SBC Fail-Safe Mode
to ensure wake-up capability.
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_1
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
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 > t
WK,Bus
). The wake-up automatically transfers the SBC into
the SBC Restart Mode and from there to Normal Mode the corresponding RXD pin in set to LOW. The
microcontroller is able to detect the low signal on RXD and to read the wake source out of the
WK_STAT_1
register via SPI. No interrupt is generated when coming out of Sleep Mode. The microcontroller can now
switch the LIN transceiver into LIN Normal Mode via SPI to start communication.
Table 18 Action due to a LIN BUS Wake-up
SBC Mode
SBC Mode after Wake
VCC1
INT
RXD
Normal Mode
Normal Mode
ON
LOW
LOW
Stop Mode
Stop Mode
ON
LOW
LOW
Sleep Mode
Restart Mode
Ramping Up
HIGH
LOW
Restart Mode
Restart Mode
ON
HIGH
LOW
Fail-Safe Mode
Restart Mode
Ramping up
HIGH
LOW