TLE9221SX Datasheet, PDF (26/91 Pages) Infineon Technologies AG – FlexRay Transceiver

TLE9221SX
Wake-up Detector
In low power modes or in the BD_GoToSleep command an active wake-up flag is indicated at the RxD and RxEN
output within the time period dBDWakeupReaction_local (see Table 5). In case the transceiver is in BD_Sleep mode,
an active wake-up flag also triggers a mode change to BD_Standby mode (for details see Table 16).
A local wake-up signal can be detected by the TLE9221SX only if the power supply uV_BAT is available. The
detection of a local wake-up is working over the whole operating range of uV_BAT (for details see Table 19).
The ERRN output indicates the wake-up event after the time dBDWake_Local:
dBDWake_Local = dBDWakePulseFilter + dBDWakeupReaction_local
7.1.2 Local Wake-up Rising Edge
The WAKE input on the TLE9221SX is a bi-sensitive input and also a rising edge (signal change from GND to
uV_BAT) at the pin WAKE is detected as a wake-up event (see Figure 17).
As on a local wake-up, triggered by a falling edge at the input pin WAKE, a rising edge also sets the local wake-
up bit and the wake-up flag respectively.
The internal state machine does not differentiate between a local wake-up triggered by a rising edge and a falling
edge at the pin WAKE. There is no possibility of distinguishing between the rising and falling edge, since only one
SIR entry is available.
WAKE
100% uV_BAT
dBDWakePulseFilter
RxD
RxEN
wake-up detection
set local wake-up bit
dBDWakeupReaction_local
uBDWake_Thr
t
BD_Sleep
Figure 17 Local wake-up rising edge
t
BD_Standby
7.2
Remote Wake-up
For a remote wake-up, also called bus wake-up, a dedicated wake-up pattern is defined in FlexRay systems. A
wake-up pattern consists of at least two wake-up symbols. A wake-up symbol on the FlexRay bus is defined as a
phase of “Data_0” followed by a phase of “Idle” or alternatively a phase of “Data_0” followed by a phase of
“Data_1”. Bus wake-up patterns are detected by the Wake-up Detector and fed to the internal state machine.
The remote wake-up bit (bit 1) in the SIR is set, if the TLE9221SX detects a remote wake-up event in a low power
mode or during the BD_GoToSleep command, regardless of whether the wake-up was triggered by a standard
wake-up pattern or triggered by an alternative wake-up pattern or by a wake-up signal via payload. At the same
time that it sets the remote wake-up bit, the TLE9221SX also sets the wake-up flag and the wake-up source bit.
In non-low power modes, the detection of a remote wake-up event is ignored and neither the remote wake-up bit
nor the wake-up flag is set.
Data Sheet
26
Rev. 1.10, 2013-07-15