TLE9221SX Datasheet, PDF (27/91 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
outputs within the time period dBDWakeupReaction_remote (see Figure 18 and Table 5). In case the transceiver
remains in BD_Sleep mode an active wake-up flag also triggers a mode change to BD_Standby mode (for details
see Table 19).
To detect a remote wake-up event, at least one of the two power supplies needs to be available.
7.2.1 Standard Wake-up Pattern
The standard wake-up pattern is defined by at least two wake-up symbols starting with “Data_0”, followed by an
“Idle” signal. The pulse width for the “Data_0” needs to be at least t = dWU_0Detect or longer. The pulse width for the
“Idle” phase shall not be below t = dWU_IdleDetect. The maximum time for the standard wake-up pattern shall not
exceed t = dWU_Timeout (see Figure 18). The pulse width for “Data_0” may vary between the two wake-up symbols
as long as the pulse width is not below t = dWU0_Detect and the standard wake-up pattern does not exceed
t = dWU_Timeout. Variation of the pulse width of the “Idle” phase is possible with the same limitations. The standard
wake-up pattern is independent of the data transmission rate.
The Wake-up Detector of the TLE9221SX distinguishes between “Data_0” and “Idle” by the differential bus
voltage. The bus voltage below the threshold uDATA0_LP is identified as a “Data_0” signal and the bus voltage
above the threshold uDATA0_LP is identified as an “Idle” or a “Data_1” signal. The Wake-up Detector does not
differentiate between an “Idle” or a “Data_1” signal.
uBus
wake-up pattern
wake-up symbol
wake-up symbol
“Idle”
uData0_LP
“Data_0”
“Idle”
“Data_0”
“Idle”
wake-up detection
set remote wake-up bit
t
dWU_0Detect
dWU_IdleDetect
dWU_0Detect
dWU_IdleDetect
dWU_Timeout
dBDWakeupReaction_remote
RxD
RxEN
BD_Sleep
t
BD_Standby
Figure 18 Standard wake-up pattern
7.2.2 Alternative Wake-up Pattern
The definition of the alternative wake-up pattern is similar to that of the standard wake-up pattern, the only
difference is that the wake-up symbols have no “Idle” signal. The “Idle” signal is replaced by a “Data_1” signal (see
Figure 19). The timing requirements for pulse width and time-out are the same as for the standard wake-up
pattern. The alternative wake-up pattern is also independent of the data rate.
Data Sheet
27
Rev. 1.10, 2013-07-15