TJA1083 Datasheet, PDF (11/41 Pages) NXP Semiconductors – FlexRay node transceiver

NXP Semiconductors
TJA1083
FlexRay node transceiver
6.3 Remote wake-up
6.3.1 Bus wake-up via wake-up pattern
A valid remote wake-up event occurs when a wake-up pattern is received. A wake-up
pattern consists of at least two consecutive wake-up symbols. A wake-up symbol
comprises a DATA_0 phase lasting longer than t_{det(wake)DATA_0} followed by an idle phase
lasting longer than t_{det(wake)idle}, provided both wake-up symbols occur within a time span
of t_det(wake)tot (see Figure 8). The transceiver also wakes up if DATA_1 phases are
substituted for the idle phases.
V_dif
(mV)
0
-500
< t_det(wake)tot
> t_{det(wake)idle}
wake-up
> t_{det(wake)idle}
> t_{det(wake)DATA_0}
> t_{det(wake)DATA_0}
+500
0
-500
> t_{det(wake)idle}
> t_{det(wake)idle}
> t_{det(wake)DATA_0}
> t_{det(wake)DATA_0}
Fig 8. Bus wake-up timing
wake-up symbol
wake-up symbol
wake-up pattern
015aaa007
See Ref. 1 for more details of the wake-up mechanism.
6.3.2 Bus wake-up via dedicated FlexRay data frame
The TJA1083 wake flag is set when a dedicated data frame emulating a valid wake-up
pattern, as shown in Figure 9, is received.
The DATA_0 and DATA_1 phases of the emulated wake-up symbol are interrupted by the
Byte Start Sequence (BSS) preceding each byte in the data frame. With a data rate of
10 Mbit/s, the interruption has a maximum duration of 130 ns and does not prevent the
transceiver from recognizing the wake-up pattern in the payload.
For longer interruptions at lower data rates (5 Mbit/s and 2.5 Mbit/s), the wake-up pattern
should be used (see Section 6.3.1).
The wake flag is not set if an invalid wake-up pattern is received. See Ref. 1 for more
details on invalid wake-up patterns.
TJA1083
Product data sheet
All information provided in this document is subject to legal disclaimers.
Rev. 1 — 10 October 2012
© NXP B.V. 2012. All rights reserved.
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