mfr4300 Freescale Semiconductor, Inc, mfr4300 Datasheet - Page 161

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

Message Buffer Status Update after Null Frame Transmission
After the transmission of a null frame, the status of the message buffer that was used for the null frame
transmission is not changed at all. The slot status field is not updated, the status and control flags are not
changed, and the interrupt flag is not set.
3.4.6.3
The section provides a detailed description of the functionality of the receive message buffers.
A receive message buffer is used to receive a message from the FlexRay Bus based on individual filter
criteria. The FlexRay module uses the receive message buffer to provide the following data to the
application
A individual message buffer with message buffer number n is configured as a receive message buffer by
the following configuration settings
To certain message buffer fields, both the application and the FlexRay module have access. To ensure data
consistency, a message buffer locking scheme is implemented that is used to control the access to the data,
control, and status bits of a message buffer. The access regions for receive message buffers are depicted in
Figure
Table
Freescale Semiconductor
1. message data received
2. information about the reception process
3. status information about the slot in which the message was received
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•
3-96, the access scheme given for that region applies to the message buffer.
3-118. A description of the regions is given in
MBCCSRn.MBT = ‘0’ (single buffered message buffer)
MBCCSRn.MTD = ‘0’ (receive message buffer)
Receive Message Buffers
Figure 3-118. Receive Message Buffer Access Regions
CFG
MSG
Message Buffer Header Field: Data Field Offset
Message Buffer Header Field: Frame Header
Message Buffer Header Field: Slot Status
Message Buffer Data Field: DATA[0-N]
MBIDXRn.MBIDX
MBCCSRn.DVAL/DUP
MBCCSRn.MTD
MBCCFRn.CHA/CHB/CCF*
MBFIDRn.FID
MFR4300 Data Sheet, Rev. 3
Table
3-95. If an region is active as indicated in
RX
SR
FlexRay Module (FLEXRAYV2)
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