PXN20RM Datasheet, PDF (747/1376 Pages) Freescale Semiconductor, Inc – PXN20 Microcontroller

FlexRay
CHI
reg(A)
cfg(A)
reg(B)
cfg(B)
FlexRay Communication Controller (FlexRAY)
PE
channel 0
cCrcInit[A]
channel 1
cCrcInit[B]
FR_A_RX
FR_A_TX
FR_A_TX_EN
FlexRay Channel A
FlexRay Bus Driver
Channel A
FR_B_RX
FR_B_TX
FR_B_TX_EN
FlexRay Channel B
FlexRay Bus Driver
Channel B
Figure 26-139. Dual Channel Device Mode
26.6.10.2 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 26-140) or the physical bus channel B (shown in Figure 26-141).
If the device is configured as a single channel device by setting MCR.SCD to 1, only the internal channel
A and the FlexRay Port A is used. Depending on the setting of MCR.CHA and MCR.CHB, the internal
channel A behaves either as a FlexRay Channel A or FlexRay Channel B. The bit MCR.CHA must be set,
if the FlexRay Port A is connected to a FlexRay Channel A. The bit 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.
Freescale Semiconductor
PXN20 Microcontroller Reference Manual, Rev. 1
26-133