NXP Semiconductors MPC5644A, Reference Manual, Page: 1588 / 1735

FlexRay Communication Controller (FlexRay)
MPC5644A Microcontroller Reference Manual, Rev. 6
1588 Freescale Semiconductor
Figure 33-149. Dual channel device mode
33.6.10.2 Single channel device mode
The single channel device mode supports devices that have only one FlexRay port available. This FlexRay
port consists of the signals FR_A_RX, FR_A_TX, and FR_A_TX_EN and can be connected to either the
physical bus channel A (shown in
Figure 33-150 ) or the physical bus channel B (shown in Figure 33-151 ).
If the device is configured as a single channel device by setting FR_MCR.SCD to 1, only the internal
channel A and the FlexRay Port A is used. Depending on the setting of FR_MCR.CHA and
FR_MCR.CHB, the internal channel A behaves either as a FlexRay Channel A or FlexRay Channel B. The
bit FR_MCR.CHA must be set, if the FlexRay Port A is connected to a FlexRay Channel A. The bit
FR_MCR.CHB must be set if the FlexRay Port A is connected to a FlexRay Channel B. The two FlexRay
channels differ only in the initial value for the frame CRC
cCrcInit . For a single channel device, the
application can access and configure only the registers related to internal channel A.
CHI
PE
cfg(A)
reg(A)
cCrcInit[A]
cCrcInit[B]
cfg(B)
reg(B)
channel 0
channel 1
FlexRay Channel A
FlexRay Bus Driver
Channel A
FR_A_RX
FR_A_TX
FR_A_TX_EN
FlexRay Channel B
FlexRay Bus Driver
Channel B
FR_B_RX
FR_B_TX
FR_B_TX_EN
FLEXRAY