NXP Semiconductors PXN2020, Reference Manual, Page: 755 / 1376

FlexRay Communication Controller (FlexRAY)
PXN20 Microcontroller Reference Manual, Rev. 1
Freescale Semiconductor 26-141
2. Read STBCSR.
The SEL field provides N and the ENB and STBPSEL fields provides the settings for signal N.
26.6.16.2 Strobe Signal Timing
This section provides detailed timing information of the strobe signals with respect to the protocol engine
clock.
The strobe signals display internal PE signals. Due to the internal architecture of the PE, some signals are
generated several PE clock cycles before the actual action is performed on the FlexRay Bus. These signals
are listed in
Table 26-12 with a negative clock offset. An example waveform is given in Figure 26-146 .
Figure 26-146. Strobe Signal Timing (type = pulse, clk_offset = -2)
Other signals refer to events that occurred on the FlexRay Bus some cycles before the strobe signal is
changed. These signals are listed in
Table 26-12 with a positive clock offset. An example waveform is
given in Figure 26-147 .
Figure 26-147. Strobe Signal Timing (type = pulse, clk_offset = +4)
26.6.17 Timer Support
The controller provides two timers, which run on the FlexRay time base. Each timer generates a maskable
interrupt when it reaches a configured point in time. Timer T1 is an absolute timer. Timer T2 can be
configured to be an absolute or a relative timer
.
Both timers can be configured to be repetitive. In the
non-repetitive mode, timer stops if it expires. In repetitive mode, timer is restarted when it expires.
Both timers are active only when the protocol is in POC:normal active or POC:normal passive state. If
the protocol is not in one of these modes, the timers are stopped. The application must restart the timers
when the protocol has reached the
POC:normal active or POC:normal passive state.
PE Clock
Strobe Signal
FlexRay Bus Event
-2
PE Clock
Strobe Signal
FlexRay Bus Event
+4