mfr4300 Freescale Semiconductor, Inc, mfr4300 Datasheet - Page 133

• Manufacturer Part Number: mfr4300
• Description: Flexray Communication Controllers
• Manufacturer: Freescale Semiconductor, Inc

3.4
This section provides a detailed description of the functionality implemented in the FlexRay module.
3.4.1
The FlexRay module uses a data structure called message buffer to store frame data, configuration, control,
and status data. Each message buffer consists of two parts, the message buffer control data and the physical
message buffer. The message buffer control data are located in dedicated registers. The structure of the
message buffer control data depends on the message buffer type and is described in
“Message Buffer
Section 3.4.2, “Physical Message
3.4.2
All FlexRay messages and related frame and slot status information of received frames and of frames to
be transmitted to the FlexRay bus are stored in data structures called physical message buffers. The
physical message buffers are located in the FRM.The structure of a physical message buffer is depicted in
Figure
A physical message buffer consists of two fields, the message buffer header field and the message buffer
data field. The message buffer header field contains the frame header, the data field offset, and the slot
status.The message buffer data field contains the frame data.
The connection between the two fields is established by the data field offset.
3.4.2.1
The message buffer header field is a contiguous region in the FRM and occupies ten bytes. It contains the
frame header, the data field offset, and the slot status. Its structure is shown in
start address
3.4.2.1.1
The frame header occupies the first six bytes in the message buffer header field. It contains all FlexRay
frame header related information according to the FlexRay Communications System Protocol
Freescale Semiconductor
3-97.
Functional Description
Message Buffer Concept
Physical Message Buffer
SADR_MBHF
Message Buffer Header Field
SADR_MBDF
SADR_MBHF
Frame Header
Types”. The physical message buffer is located in the FRM and is described in
of the message buffer header field must be 16-bit aligned.
Figure 3-97. Physical Message Buffer Structure
Frame Header
Buffer”.
MFR4300 Data Sheet, Rev. 3
Message Buffer Header Field
Message Buffer Data Field
Frame Data
Data Field Offset
Slot Status
Figure
FlexRay Module (FLEXRAYV2)
Section 3.4.3,
3-97. The physical
133