FlexRay Communication Controller (FLEXRAY)
MPC5510 Microcontroller Family Reference Manual, Rev. 1
Freescale Semiconductor
30-3
Preliminary
Figure 30-1. FLEXRAY Block Diagram
The protocol engine has two transmitter units TxA and TxB and two receiver units RxA and RxB for
sending and receiving frames through the two FlexRay channels. The time control unit (TCU) is
responsible for maintaining global clock synchronization to the FlexRay network. The overall activity of
the PE is controlled by the sequencer engine (SEQ).
The controller host interface provides host access to the module’s configuration, control, and status
registers, as well as to the message buffer configuration, control, and status registers. The message buffers
themselves, which contain the frame header and payload data received or to be transmitted, and the slot
status information, are stored in the FlexRay Memory (FRM).
The clock domain crossing unit implements signal crossing from the CHI clock domain to the PE clock
domain and vice versa, to allow for asynchronous PE and CHI clock domains.
The FlexRay block stores the frame header and payload data of frames received or of frames to be
transmitted in the FRM. The application accesses the FRM to retrieve and provide the frames to be
processed by the FlexRay block. In addition to the frame header and payload data, the FlexRay block stores
the synchronization frame related tables in the FRM for application processing.
The FlexRay Memory is located in the system memory of the MCU. The FlexRay block has access to the
FRM via its bus master interface (BMIF). The host provides the start address of the FRM window within
the system memory by programming the
System Memory Base Address High Register (SYMBADHR)
and System Memory Base Address Low Register (SYMBADLR)
.
All FRM related offsets are stored in
offset registers. The physical address pointer into the FRM window of the MCU system memory is
calculated using the offset values the FlexRay memory base address.
Clock Domain Cross
ing
PE
TxA
RxA
TCU
config
SEQ
CHI
HIF
SEARCH
LUT
BCU
FR_A_RX
FR_B_RX
FR_DBG[0]
FR_A_TX
FR_A_TX_EN
FR_B_TX
FR_B_TX_EN
FR_DBG[1]
FR_DBG[2]
FR_DBG[3]
FLEXRAY
Peripheral
Bridge B
XBAR
BMIF