mfr4300 Freescale Semiconductor, Inc, mfr4300 Datasheet - Page 135

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

Each individual message buffer has a message buffer number n assigned, which determines the set of
message buffer control registers associated to this individual message buffer. The individual message
buffer with message buffer number n is controlled by the registers MBCCSRn, MBCCFRn, MBFIDRn,
and MBIDXRn.
The connection between the message buffer control registers and the physical message buffer is
established by the message buffer index field MBIDX in the
The start address SADR_MBHF of the related message buffer header field in the FRM is determined
according to
3.4.3.1.1
The set of the individual message buffers can be split up into two message buffer segments using the
Message Buffer Segment Size and Utilization Register
a message buffer number n <= MBSSUTR.LAST_MB_SEG1 belong to the first message buffer segment.
All individual message buffers with a message buffer number n > MBSSUTR.LAST_MB_SEG1 belong
to the second message buffer segment. The following rules apply to the length of the message buffer data
field:
Freescale Semiconductor
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all physical message buffers associated to individual message buffers that belong to the same
message buffer segment must have message buffer data fields of the same length
the minimum length of the message buffer data field for individual message buffers in the first
message buffer segment is 2 * MBDSR.MBSEG1DS bytes
the minimum length of the message buffer data field for individual message buffers assigned to the
second segment is 2 * MBDSR.MBSEG2DS bytes.
Equation
Individual Message Buffer Segments
SADR_MBDF
SADR_MBHF
MBCCSRn
3-2.
SADR_MBHF = (MBIDXRn.MBIDX * 10) + 0x800
Figure 3-98. Individual Message Buffer Structure
Message Buffer Control Registers
Frame Header
MBCCFRn
>= MBDSR.MBSEG[1,2] * 2 bytes
MFR4300 Data Sheet, Rev. 3
Message Buffer Header Field
Message Buffer Data Field
MBFIDRn
FrameData
(MBSSUTR). All individual message buffers with
Message Buffer Index Registers
Data Field Offset
MBIDXRn
Slot Status
FlexRay Module (FLEXRAYV2)
(MBIDXRn).
Eqn. 3-2
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